While people are getting beta codes, make sure that when you go to redeem your beta code here :
http://www.bungie.net/en/User/coderedemption
Also enter the following codes. These codes were distributed on collectors cards at the trade shows last year and are supposed to unlock some in game content once the game launches:
Warlock: YKA-RJG-MH9
Hunter: 3DA-P4X-F6A
Titan: MVD-4N3-NKH
Rixis: TCN-HCD-TGY
Old-Russia: HDX-ALM-V4K
Hive: 473-MXR-3X9
Moon: JMR-LFN-4A3
Gjallorhorn: HC3-H44-DKC
Duke MK.44: 69P-KRM-JJA
The Tower: 69P-VCH-337
The Hive, Ogre: 69R-CKD-X7L
Valley of the kings, Mars: 69R-DDD-FCP
The Fallen: 69R-F99-AXG
Red Death: 69R-VL7-J6A
Caval: 69X-DJN-74V
Venus: 6A7-7NP-3X7
Vex: 6A9-DTG-YGN
People in the UK who have preordered and have not received a beta code can just pre order on Amazon.com with their Amazon.co.uk login details, get a code within 5 minutes, then cancel on amazon.com.
With any beta code, you can redeem it for any platform. so pre order the 360 version, redeem the code on Bungie's site, and then when the beta is properly announced, you can then select which platform to get the actual download code for, so get a PS4 download code for example.
If people have not been keeping up with the details of the game this is the best summary video around. Its long but covers a lot.:
https://www.youtube.com/watch?v=hLQFmob-vsM