On one hand, I love the new instance as it's, well, new.. and also provides a nice challenge to geared players in heroic mode. One thing that I do dislike is how heroic mode is way too dependent on CC that non-cc specs have a hard time finding groups for it.
Here is a rundown of each class and what CC is available for them during the course of the instance and primarily the 3rd boss (*shudder*).
Feral Druid's and Resto Druid's usually come to fill a tank or healing role but some Feral Druid's can be used for DPS as well. If you're in this roll, your best CC is just to assume bear form and OT when needed. Balance Druid's can spam Cyclone but diminishing returns can turn around to bite you in the feathers. Another option for Balance Droods is to spam Cyclone until the mob is immune and then either Panzerkin tank it or assume bear form until it's your mobs turn in the death rotation.
Paladins are a lot like Druid's in a sense that if they are Prot or Holy they are there to fill a specific role. A Ret Pally can either use Turn Undead on the Demon mobs (which we all know how well fear works in instances) or just slap on a sword and board and OT until it's his/her mobs turn to die. Just make sure that if you are stuck in this roll to keep Righteous Fury up but to turn it off when you're DPS'ing.
Prot Warrior's are there to tank while Arms and Fury are there to spread the pwn sauce. That's a given. Slap on a shield and OT just like Druids or Pallys. It's really all you can do.
MrT is pretty Lock-friendly with the amount of demons mobs. The succubus mobs make amazing pets and can take on mobs by themselves. I totally recommend enslaving one each pull, putting it on a mob to OT and then releasing and killing it in the end. You don't want to keep the same succubus each pull in fear of it breaking in combat. The seduce spell they use is brutal and the mob can be DPS'ed without breaking it so spam it! During the Delrissa fight there are 2 possible Demon mini-boss adds that can be banished so keep an eye out for those.
Nothing new here. Sheep whatever can be sheeped and Frost specced Mages don't be afraid to frost kite mobs when needed. Arcane Mages specced in to Slow will also find a lot of use for it here.
Holy/Disc priests are here to heal so let the Shadowpriests Mind Control when needed. I'm not sure if Delrissa's adds can be MC'ed so if not be prepared to step out of Shadowform and backup heal if needed. As for CC during this fight, I honestly have no idea but i'll edit this post after I talk to our guilds Shadowpriests to see what they do.
Shaman have it rough and need to get creative. Rank 1 Frost Shock and Earthbind Totem is your friend during the Delrissa fight. Pick one of the adds that aren't a caster or a Rogue and keep at it until the rest of your group gets the nasty Priestess down. Also don't be afraid to drop your Fire/Earth Elemental away from the CC'ed mobs if needed and pop Heroism early to help your group down Delrissa.
Rogue's have it pretty easy with Sap and being able to blind broken CC'ed mobs but also being able to Evasion tank as a last resort.
Also pretty self explanitory being able to keep mobs trapped during the encounter but also Beast Mastery Hunter's can OT with their pet. Even if their pet dies it should give the group enough time to pick it up before the Hunter takes a dirt nap himself.