Microsoft/Bungie has announced the start date for the Halo 3 beta: May 16th.
The beta will roll out globally at 1:00 p.m. GMT (8:00 a.m. ET, 5:00 a.m. PT). The beta will run through June 7 at 7:59 a.m. GMT (June 6 at 2:59 p.m. ET, 11:59 p.m. PT). A Halo 3 beta key is still available for those who purchase the Xbox 360 game Crackdown.
The beta will feature three new maps and new vehicles and weapons. Many features are being hidden though until the official release of the game in the Fall.