Bungie have announced that they are looking for people to beta-test their upcoming game - the game being published by Activision, that will be released for PC, Playstation 3 and Xbox 360, and that has absolutely nothing to do with Halo. Not everyone will be able to get in, but they expect to have use for "hundreds of thousands of gamers", so there's probably a pretty good chance to be chosen.
We're quite surprised that Bungie are already ready to talk about a beta for their next game, but then again they don't mention a time frame for when testing will begin. If you want to take a shot, just head over to the official Bungie site and sign up.