We basically did on a larger scale the arranging of groups around the core of the battle with the tank-sound familiar. We used most of the south part of the arena for it, but stayed away from the entrance as to have her not accidentally reset. I think the biggest key was MANA drain and a set number of healers organized to heal in rotation. Important as well was on phase II have everyone stunn, kick, or whatever works to keep her from healing herself (don't recall specifically which ones worked for each class). Have folks provide a constant mana drain and then on phase II send in all dps. Thats basically what we did that day and worked fine, better than what we thought. We did have a few casualties, but in a battle like that its to be expected.
Oh..but in the newest patch they fixed the bug which kept her spawn from attacking-so I guess all bets are off and have to come up with a twist of a new strategy now.
Saber
