My guild and I just cleared out Karazhan for the first time tonight. We were having trouble with Prince Malchezzar and his stupidly random infernal drops. We were actually in a bad situation when we actually killed him. We were using door positioning and an infernal dropped right on top of Prince so our melee dps had to do other things while our healers kept healing the tank who is taking constant infernal and Prince damage.
Afterwards, Netherspite was a piece of cake. Only complication was healer positioning to heal ranged beam interceptors. Aside from the two people dieing from that, easy down and clear. For kicks half the group did Heroic Slave Pens afterwards.
Now I'm sitting on 77 Badges of Justice and waiting for the new purchasable gear in 2.4. I'm disappointed that there is no caster staff, but I am intrigued with spell hit being on the gear instead of spell haste. I'll have to consider if it's worth the investment since my spell hit is nearly maxed currently.
We'll be poking our heads into Zul'Aman next week after a hopefully clean run of Karazhan.

Anyone else have some WoW stories they would like to share?