“The Halo 3 Multiplayer Beta will go live on May 16th at 12:00 AM PDT and run through June 6 th at 11:59 PM PDT. That means that folks who purchased specially marked copies of Crackdown, or won a spot in the Beta through the “Rule of Three” or other regional promotions, will be able to log into their Xbox Live Gold accounts, download and play the Halo 3 Multiplayer Beta and enjoy an early peek at the multiplayer aspect of the game.” -Bungie.net
Woo! Finally- a date!