Tanked Heroic Drak'Thron Keep last night with some guildies, and my new protégé healer. It was relatively smooth—until we hit the dino boss. It's rather difficult to gather all of those adds—but for a fresh lvl 80 priest, and a rather under geared tank you should probably kill them all before you attempt the boss. It wasn't an epic fail, just a delay. I wiped them once, and the priest wiped us once (I know this because I was the first one to die, thus telling me he wasn't able to keep up).
The thing that excited me the most was that I was keeping up with the threat put off by one of my Guildie hunters (he's such an awesome player, three characters completely decked out in armor). He informed me later that he was using MD—something which FollowOtherness had suggested on one of my previous posts. The little rogue in my group, one of my good friends, was on the floor a lot… not necessarily because of my tanking, but because the healer couldn't keep up with me and everyone else. She wasn't even pulling aggro, she was more or less one shot--or "insta-death" as our healer put it. At any rate, it was a great run--a few deaths, but fortunately we had a patient PuG member, so it was relatively easy going.