Beyond the opportunity to explore the internet from the comfort of your couch, you'll also get "personalized dashboard recommendations" (whatever that means), and "enhanced category search and discovery features."
Like with so many betas, participants won't be able to write about their experience or take pictures or anything like that until the required non-disclosure agreement expires. But hey, you'll be part of a super secret club, so there's something.
Update: Looks like the beta's full up, y'all. Congrats to those who got in!