That said, enough has been revealed about monk healers that it's time to look at the basics and speculate wildly about the rest. Commence speculation, gogogogo!
It appears that there will be two aspects to being a melee healer. One is that you must be within melee range of your healing targets for direct healing (or at least, nearby). The other is that apparently you'll have access to indirect healing through melee attacks on enemies.
Being a "melee healer" (that is, a healer who works at melee distance rather than from range) was one of the few areas that existed for Blizzard to expand into to create a new style or niche of healing. There was some very rudimentary (and ultimately non-existent) form of being a melee healer in the holy paladin role, as Seal of Insight refunded health and mana to the paladin if he or she stood in melee range of a mob and hacked away. It didn't prove to be worth it enough for paladin healers to actually melee mobs and bosses in instances, though, as paladin healers pretty universally stood at range like all other healers.
It wasn't clear, then, what mechanics would enable a healer to stand in melee. The mechanics would have to make standing in melee essential to being successful as a healer and, further, feel rewarding as a play style. Rogues stay in melee range because their DPS depends on it and because it feels fun to position themselves for blade attacks. It has to be both necessary and fun.
What little we've heard from Blizzard about monk healers (Mistweavers) starts to fill in the road map for how Blizzard believes these two goals can be accomplished for a healer. It seems to hinge on two key concepts, so let's look on them. (Don't worry, wild and baseless speculation is still ahead!)
Since Mistweavers will apparently need to be nearby allies that they are directly healing, mobility is a must. Melee classes like warriors and rogues have crucial mobility abilities, like Heroic Leap, Sprint, Intervene, etc. This makes sense since melee classes have much stricter positioning and range issues than casters and hunters.
Mistweavers will have much stricter positioning and range issues than other healers, so they're going to need the mobility help as well.
Meet Roll (for any linked monk abilities, I'm linking the battle.net page on monks, which has three sample abilities). The description is pretty bare bones, reading only "Roll a short distance." We can envision this, however, being a fundamental way to quickly get from one place to another, perhaps equivalent to a mage's Blink (minus the "poof" graphics). It has no stated cooldown, though it has a cost in chi. Blizzard has already stated, during Blizzcon, that Mistweavers will use mana instead of chi, so it remains to be seen what the cost is in mana.
Of course, the possibility also exists that Roll won't be available to Mistweavers, but that strikes me as implausible and silly, for the reasoning stated above that melee-based healers will need mobility. More likely, all abilities will cost chi as baseline, but will all have their costs transformed to mana when you spec Mistweaver.
I'd expect more movement-enhancing abilities, because you can't ask a healer to have extremely tiny ranges to their direct healing spells and then expect them to walk around, using their own legs like suckers. Without things like Roll, the message is "Roll a healing class that has sensible cast ranges."
That said, if there are a number of movement-enhancing abilities, we start to see an interesting play style emerge. A cross between a protection warrior (for whom getting around the battlefield quickly is a forté) and perhaps a restoration shaman (the healing spec that has the most demanding positioning requirements). Zip around the battlefield healing small knots of allies. The melee clump here, a ranged clump there, the dying-in-fire clump...no wait, never mind.
Healing props are nothing new. Restoration shamans have had a multitude of totems forever. They lose totems in the couch cushions and groan when totems muck up the washing machine because they left them the pockets of their jeans by accident.
Totems have generally provided either a passive buff (long-lasting totems that just buff everyone in range) or active effects (short-lived totems that do something like damage, mana restoration, taunting, etc).
Statues are something in between. They don't, in and of themselves, provide a buff or an active effect. What they (and by "they," I mean the one statue that has been revealed so far) appear to do is act as a proxy, allowing the monk to act through them from a distance.
Take a look at the Statue of the Jade Serpent. The tooltip reads:
Summon a statue at the target location. Anytime you deal damage, a nearby friendly target within 20 yards of the statue will be healed. You can have up to 3 Jade Dragon Statues active at a time.
A quick note before we go into consequences of this specific statue. Do we have a misprint or a hint of things to come in the "You can have up to 3 Jade Dragon Statues active at a time?" The name of the spell contains "Jade Serpent" not "Jade Dragon." That suggests that either they typed the wrong thing for that sample tooltip or else "Jade Dragon" is a class of statues, of which the Jade Serpent statue is just one. Interesting, though it doesn't tell us much except there may be a whole statue system rather than just one or two statue spells.
Looking at this specific spell, though, we see perhaps the other foundation for a melee healer...agents that can allow you to act "in melee range" in different locations. You're standing next to the boss, spin-kicking it happily. Your glass cannon mage is about to shatter from the stress of all the DPS he or she is putting out, at a far-away location. You either have a statue there or you quickly put one there*. Your next spin-kick gets turned into healing energy and flows to the statue at which point it's redirected into the mage, filling his or her health bar and the DPS continues uninterrupted.
*Note that the statue is summoned at a target location, suggesting that there is a range for dropping the statue rather than the statue dropping where you're standing like shaman totems
You didn't have to move away from the tank and melee clump you were healing with your direct healing spells. You just had to shift from acupuncturing your melee mates to delivering crane kicks to the boss' jaw in order to deliver heals to someone nowhere near you.
If the "Jade Dragon" language really does imply classes of statues and therefore an entire statue system, what else might statues do for us? We want to avoid statues being totems by another name, so we want to keep our thoughts away from passive buffs (like added armor) or active effects (like summoning a temporary pet or shooting fireballs) and think more in terms of them being agents or instruments of the monk's will.
Here's an example: Statue of the Cloud Serpent
Summon a statue at the target location. Anytime you deal damage with a Death Monkey Super Kick, you will be teleported to the statue. You can only have 1 Statue of the Cloud Serpent active at a time.
(Death Monkey Super Kick is just a place-holder for a baseline monk attack. It may not be called that.)
This allows you to use one of your fancy monk attacks to instantly jump to another place (like a stack-up spot or a place across the raid encounter room where a second group is fighting another member of a "council" type of raid boss, etc), the better to get around the battlefield.
It's just an idea, the type of thing that I feel makes sense for a statue system that would differentiate it from the totem system. Agents in the field..."my statues r in ur raid, spying on u."
Also, monks can use fist weapons in addition to one-handed swords, maces and axes. Might we finally see the first sanctioned dual-wielding healing spec? Almost certainly not; Blizzard is very conservative in some ways and clearly has their own conceptions of what each role "looks like," and I don't think dual-wielding healers fit their mental models. For a short time, restoration shamans were going deeply enough into the enhancement tree to pick up dual wielding in order to dual wield spellpower weapons (back when dual wielding was a talent and you didn't have to invest 31 points into a specific tree). Blizzard shortly thereafter made all one-handed spellpower weapons "main hand," rendering it impossible to hold one in the off hand. They also made talent tree changes to crack down on inventive "hybrid specs" that produced results that Blizzard hadn't planned on.
So, my guess is that they don't like the idea of healers dual wielding and will not be producing any spellpower weapons that can be equipped in the off hand. They will probably also lock dual wielding to the DPS and/or tanking specializations, to avoid any experimentation with an agility off-hand to increase damage done (and, therefore, Jade Serpent healing done).
Even still, one can hope. Hope brought us
Melee Healing--Just Right Crazy Or Not Crazy Enough?
There's a strong chance this won't work. Remember, they had a "new concept" in mind with their last new class, death knights. That new concept was that you could tank or DPS in any spec, with the presence you used being the most important signifier to your role. That proved to be a bear to balance properly and they ultimately decided it was a failure and reconfigured death knight specializations more traditionally, with a dedicated tanking tree and two DPS trees with a different playstyle each.
So they may decide over the course of 5.0 that melee healing is a failed concept as well and eventually Mistweavers will join their other healing brethren at the perimeters of the fight, shying away from contact. They may even decide that if melee healing isn't on, then there's no point even having a monk healing class (because what would it bring that all the existing healing specs do not?).
So if you enjoy healing, spend some time playing a monk this next expansion. You'll get to see at least one vision of what melee healing might look like and the chance to play a monk healer may not last forever. There are some interesting concepts shaping up for Mistweavers, based around unique mobility, damage dealing and proxy healing. It may work, it may not, but you may want to have seen it for yourself before Blizzard makes their ultimate determination and either changes the spec or eliminates it for another DPS spec.
Just don't get too attached to the spec, as our rather Buddhist Pandaran friends would advise.