Review Board is participating in the 2009 Summer of Code. If you're a student interested in working on Review Board for the summer, you can apply between March 23 and April 3rd.
As a starting point, we have a list of ideas for features we'd like to see included in Review Board.
There's a reviewboard-gsoc mailing list for discussion and announcements. We strongly encourage all students and mentors to sign up to this. We expect it will be fairly low-traffic.