Melee trains are going to be so sick this expansion. There's so much anti-cc already, before adding this. Tangentially, I don't know what blizzard is doing; I've played a few classes on beta and they have a godawful damage rotation/design.
I played a few hours of Shadow Priest last night. The beta is pretty buggy; you can chain 8+ mind blasts together. Psychic Horror lasts too long (8s with 3 orbs). Healing is completely baked into Devouring Plague. The class felt strange with PW:S, Flash Heal, and Devouring Plague being the only heals worth casting. As Narthy said, sticking a fear with the increased cooldown feels impossible at times. Psyfiend helped mitigate this on live. Fear should be baseline and stay at 30s cd. Vampiric Embrace was gutted.
The good: Getting 3 shadow orbs from Mind Blast glyph helps Shadow immensely in the opener. Having an extra 2 orbs is a strange choice, but orbs are plentiful and it helps create double devouring plague or devouring plague + psychic horror combos. The game plays a little slower, which helps Shadow not get gutted in the opener in 2s.
We'll have to wait and see on more balancing to see where Shadow Priest goes. The damage is crazy good right now and the off-healing is powerful (but feels clumsy spamming Flash Heal). Yet, it feels like once Psychic Horror and MB bug are balanced/fixed, Priests are going to really feel how weak their CC is.
I don't understand the direction they're taking with MW monk. Ring of Peace DRs with Paralysis, increased GCD to 1.5, no dispel protection, no chi from soothing/crackling, separating fistweaving and mistweaving. Making chi more difficult to generate on top of Enveloping Mist having no dispel protection will be really frustrating. I don't mind the play style where we focus on keeping renewing & enveloping mists up, but that seems inherently more difficult with less chi and players spamming purge/dispel. We're becoming a channeling healer with no direct heals on the move (unless you Glyph Expel Harm) that have a 1.5s GCD.
Healing spheres had to go, but I'm not enthusiastic about the new model for healing for MW.