It's going to be very interesting to see whether or not Mavericks solves a lot of these problems since it has full OpenGL 4.0 support (though only partial 4.1 and almost nonexistent 4.2 support). If Mavericks solves the graphics glitches, it may well be worth my while to set up a Chameleon boot into Mavericks on my Mac Pro 1,1 just for my Blizzard games.
Diablo III and World of Warcraft Technical Support MVP
Official Mac Tech Support Forum Cookie™ (Mint Chocolate Chip)
Guaranteed tasty; Potentially volatile when dipped in General Forums Syrup®
Caution: This cookie bites back.