Don't know if it's already posted before, but i managed to get GW running on mac :)
It actually works perfectly fine hehe, except that i haven't found a way to go full screen yet... but it's a start ^ ^
But just some information, i'm not using a real mac, i'm using osx86 which is mac on a pc. But it works just like mac.
Is there anyone here with the new series of intel macs that can try this technique out for a real mac? it should work though, quite sure of it...
Use the program: CrossOver
Just install the program, copy your guildwars instalation to your mac, make sure you have about 10gb free space and just double click on the gw.exe wait a while and it should pop up with the install screen.