fortheovermind on 02 March 2010
I'm not sure if it'll be on Mac at all, however I did find a site giving out closed beta access for Diablo 3, so I'm sure you can find out there.
They said they are doing it as a preventative measure against the rampant invite selling and scamming happening with the Starcraft 2 beta.
I just signed up without entering any personal information or paying any kind of money.
For those who want to try it out, the URL is here, I've shortened it: http://diablo3betakeys.blogspot.com
Hope you guys can join me and get some keys.
