I have a 60 mage and aoeing is nice, but once you hit 60, you've done it so much i automaticly specced out of it.
It's pretty good for grinding, and unless you're going to farm ZG rep or something for money (which now evidently is an exploit, WTF BLIZZARD) it quickly gets rather boring.
Now that you can't aoe farm the elementals in NW Silithus too (another WTF BLIZZARD), aoeing is kind of.... pointless... also seeing that if you're going to be aoeing SM or something at 60, you can do so with a ice barrier-(aoe speccing, and actually speccing frost are different :P) gather-frost nova-run a few steps-flamestrike-spam AE until they're dead
It's pretty dang fun doing it in SM GY with all the little ghosts, or in the first big room just gathering them all