I sind up and I (only) got a "Thank you" via email. And now?
Same here.
This is a standard type of thing for a start-up.
They get you to visit the site, sign up, then after however-long-it-darn-well-takes-to-have-a-beta-version, they email you and ask you to hop on board.
I signed up as well. Same deal. But, I knew from the initial screen that was what it was.
Just be patient. They'll update you when they have something to deliver.