Installer doesn't work and it wants things in your /library directory to be case insensitive as well. This just seems like poor/lazy programming that isn't aware of how a Mac (can) work. Seems like a quick patch, but Blizzard didn't do it for WoW or SC2 beta and its been a known issue for some time.
I was able to make Steam work by putting it on a disk image with a case insensitive file system and symlinking all of the directories it wanted to directories on that image.
