Microsoft and Bungie finally announced today that the Halo 3 Beta will begin on 16 May at 1:00PM GMT and continue until 7 June at 7:59AM GMT.

The beta promises to offer the definitive glimpse at Halo 3's gameplay - how it 'feels', what the transition from Xbox to Xbox 360 has been like for the series, and how Bungie has tried to improve on a near-perfect multiplayer formula. Those who received an invite through purchasing marked copies of Crackdown, the "Rule of Three" program, or being one of Bungie's best fwends will get to gun their way across three maps - Snowbound, High Ground, and Valhalla. You will also, of course, be able to play with all of the new weapons and vehicles that have been slotted into Halo 3. Just keep in mind that this is a Beta, and Bungie is doing this to gather information just as much to drum up [even more] interest for the title - you will encounter some bugs and inconsistencies.

Hit the jump to see the announcement-accompanying video that demonstrates what you can expect to play with in the Beta.