The Windows Vista Team Blog published a Windows Vista RC1 availablity update

OK, so I've been getting RC1-related questions a lot, both via blog comments and directly over email: Will Microsoft open testing sign-ups again when RC1 is released?

Yes.

Will the Customer Preview Program be available for those who missed out on Beta 2 to sign up and get RC1?

Yes.

If I participated in Beta 2 by downloading a PID and the build, will I be able to participate in RC1 automatically?

Yes.

RC1 Availability Update