My guild is in heroic modes right now. I was part of their 1st core group during Firelands and then again at the end of Dragon Soul back in Cataclysm. My old job was killing me with scheduling though so I had to give up my spot.
I played a Mage all through Cata though. Tier 11-13. Arcane for the most part and then Fire at the end. Even got one of the Firehawk mounts from Ragnaros before Mists came out.
Nice! My guild has never been able to get heroic raids going. People always start burning out near the end up 10 man content. We have been together since TBC, though, so no one wants to leave.
We should be in terrace 10 man by february.