So, the cat is finally out of the bag. I never played a monk in any edition but 3rd, and that joke of an experience is better left unsaid.
This has come as a big surprise to, basically, everyone: the monk utilizes the psionic power source instead of the highly speculated ki power source. They explain their reasons in the accompanying Design & Development article, and I agree with all of their points. The fact that they are strongly considering building samurai as conceptual feats works well with Josh's own style: he's playing a "samurai" in another game in which his actual class is the barbarian.
I like that the use of a monastic tradition is enforced, and no longer merely implied. The article only features on (Centered Breath), but obviously we can expect more when the class is actually released. I mostly like this since it works well with character backgrounds and also guides the choices and style of your character, but it looks simple and flexible enough that DMs will be able to easily make their own traditions specific to their campaigns.
They seem to be Dex- or Str-based with a few kickers from Wisdom, which is basically how you did a monk before, and an AC boost if you arent using armor or shields. It also looks like they maintained the 3E unarmed attack mechanic: it deals more damage that a typical unarmed attack, gets a proficiency bonus, and you can use any part of your body to simulate it. You can use the Enchant Item ritual to add crazy shit to your unarmed attacks. This can be represented in a number of ways (I'm a fan of mystical tattoos, myself), but I'm sure that 4E detractors will sling their best denigrations.
However, monks can also use actual weapons as, well, weapons or implements. I never liked that in 3E that had a bunch of cool-looking but ultimately shitty weaponry for characters to imagine finding a use for, but ultimately sticking to the stuff that not only didnt require a feat but was also better anyway (such as the claw bracer). Monks can use several weapons that function just as well as their unarmed attack, but can also use them as implements for powers that call for it. Basically, expect to see monks toting around quarterstaffs and the like and actually using them.
Many of the powers have the Full Discipline keyword(s?). The wording is a bit confusing, but as I understand it that if a power has the keyword it is essentially an attack and movement option paired up together. You are limited to the "use of one full discipline power per round", which I take to mean that you cannot use the attack technique of crane's wings and then switch to the movement technique of dragon's tail, but can use the attack and movement technique from either power in the same round.
I really like the structure of the monk powers. They want these powers to represent fighting styles, and having so many of the powers have thematically tied attacks and movement really makes the concept work. Dragon's tail lets you make a Dexterity vs. Fortitude attack that deals 1d6 damage and knocks an enemy prone. The movement technique lets you switch places with an ally or prone enemy, and if you use both I can really imagine the monk flipping the enemy head over heels behind her, or just throwing them.
Its good because it helps support the narrative aspect of 4th Edition that I didnt see so much in other editions. Sure, you can describe attacks and spells in any edition, but the mechanics didnt always support powerful strikes that can knock enemies back, or stun them, or trip them. These all flow really well to create a consistent cinematic experience.
However, like many of the newer classes this is going to create more bookwork on the player's end. Many powers have two parts to them that you will have to track and utilize. I think its a matter of work vs. reward, though. You have to track more, but you have many more options than the typical class does since over half your powers are going to grant you potential movement kickers.
For me this just means that I'm going to dig the class. I have a knack for commiting mechanics and rules to memory, to the point where I was memorizing the attack bonuses for the rest of the party in Red Jason's Punjar campaign.
The article also has a pair of paragon paths: the radiant fist and the ghostwalker. Radiant fists are monks who worship deities and get a booster shot of divine power from them, while ghostwalkers like to weaken and teleport a lot, thanks to the help of spirits (and sometimes its the enemy's soul that they are using for 'port fuel).
A bit of strangeness: leaf on the wind is one of the level 2 utilities. For those not keeping track, its also a level 1 warlord attack. I'm not necessarily opposed to reusing names, but this might cause confusion in case anyone in your group actually plays a warlord.
My end thoughts are that this class looks extremely promising. Its only a playtest, and I fully plan on making a monk and seeing how well it fits. I have high hopes that it will be an actually enjoyable experience, especially since Wizards made the bard useful.