Blizzard recently announced that Diablo 3 has begun! At the beginning most of the beta testers will be friends and family of Blizzard employees but soon more people will be able to access it. Stay tuned for more updates and meanwhile don’t forget to change your beta settings by going to your blizzard account, login and then on the right menu click beta profile settings.
There you will be able to download the profiler and after you run it, Blizzard will know that you are interested in beta participation and your system specs in order for you to have a chance to be included in the beta!
Good luck and stay tuned!