Quite a few people have emailed me pointing out that LEGO Universe has their Beta signup openly listed:
http://us.universe.lego.com/en-us//Beta/Default.aspx
This may only be for people in the US/North America. It does require a LEGO Id and there is no guarantee you’ll get in, this is the email you’ll first get:
Thanks for signing up for our beta testing. Your registration has been successfully saved. If you are chosen to battle the dark forces of Maelstrom in the LEGO Universe Beta test, you will soon receive a key to enter the universe. Good luck!
Sincerely,
LEGO Universe