Through registry edits (simple ones), Warcraft 3 can support any arbitrary resolution. Here are the results:
To answer the original question, you can crank catalyst settings (8x SSAA at 1440p) to the point where you become GPU limited in this game. I've done so, and ran into a GPU bottleneck with the rig in my signature, but I just put everything on maximum to see what happened. You could easily get that same IQ without cranking things so high and you wouldn't come anywhere near a GPU bottleneck. Playing custom maps, I routinely run into CPU bottlenecks though. :thumbsup: