Most guilds raid in Karazhan with two mages, two priests, one paladin, two warriors (or maybe one and a hunter), one rogue and one warlock and one druid. Maybe not exactly this setup everytime; but something very balanced on main roles like this one: Four or five characters with healing abilities, three or four with tanking ability and also that many on DPS.
In Aion we have an interesting setup for this kind of raid. We surely lack many tanks and in abundance of mages, rogues and druids. So we are going like this:
Thoiin - Warrior - Main Tank
Partola - Paladin - Off-Tank / Main Assist
Koli - Rogue - DPS
Kyrn - Rogue - DPS
Zuza - Mage - DPS
Zuhu - Mage - Wanna-be-DPSer
Cyrn - Warlock - Fearmonger
Charelle - Druid - Healing / Battle Resurrection
Jittai - Druid - Healing / Battle Resurrection
Sylivan - Priest - Healing
This raid setup does fine up to 4-5 bosses in Karazhan, easily beating Attumen, Moroes, Wizard of Oz Encounter at the opera and Maiden of Virtue without any wipes. DPS is nice, healing is good and battle resurrection saves the day at boss fights. Interesting raid setup, but works fine since druids can tank, paladin can heal whenever needed.
Ah, since the Curse of Zuhu persists, we need more and more healing machines! On the other hand one of our druids changed his main character to a mage, an imba mage; so I wonder how things going to change for me. Since I am the weakest DPS'er within mages in the guild. Time will tell.