Neither we nor the devs know yet.
How are raids going to work? I don't see a tank going in, holding aggro, while casters cast essentials spells like slows and debuffs, dps strategically unload, and healers fight to keep you alive.
What I see is everyone running in and using AoE spin attacks while making a big hole in the ground. (joke for the most part)
Do we have any comments on how they feel raid and group encounters will work? I've read a few holy trinity comments but with all the variations in classes, it sounds like GW2 meets Rift which had its own issues.