I think people are starting to suffer from signup fatigue (even with just 3 boxes). Wherever possible, services should get right into the kernel of the experience and ask for registration later.
[0] Don't look here for a link from me, I'd rather not encourage them by sending traffic their way.
Came here to write a comment, then decided to go back to the site. It accepts joe@example.com as a valid email. Typed throwaway password.