honestly i do not look at FPS.... some places say 60 is the max for wow. i dont know.
but the game runs very smooth. after about 50-60 fps all the rest is waste.
game runs very smooth with 25+ people all casting at the same time.
i also run 2 wows from time to time and have no problems with one wow on each screen full sized with no problems.
Wow WoW 2 account your a deticated player lol. after 60 you wont see a diff becaus most screens have a 60 fps refresh rate. But there are some ive seen with 75ish. So in that case you would see the extra 15 FPS and then anything over 75FPS would not be noicable.