Unless I'm mistaken. the installer and updater for Warcraft 3 as well as Starcraft and Diablo 2 are Rosetta apps, even though the games themselves are universal. Since 10.7 removed Rosetta you can't install the games or update them any longer, though if you have a preinstalled copy you can continue to play.
The installer isn't the issue - I have an old mac mini I installed the game on to.
Half the textures don't load. The game menu is basically a whole lot of black buttons without labels, and if you get a game running by muscle memory, pretty much most of the screen is black. I spent a good couple of days trying to find some sort of resolution, all I found was other users complaining about the same issue.
This is what I meant when I complimented Blizzard -- they updated WC3 and the expansion to Intel, and the intel installers can also be downloaded from battle.net now.