We're happy to accept patches for different SCM servers. Review Board heavily relies on patches from contributors, and we'll pretty much tell you if there's a reason we won't accept it (which generally falls into the following categories: 1) the timing isn't right (should be an extension, for example), 2) it's too specific to a particular setup, 3) it's not implemented right (in which case we'll work with you on that).
Right now, we're in a feature freeze, so this won't go into 1.0. It can get into the next release (probably 1.1) though.
Whenever you feel it's ready for inclusion, go ahead and post it up on http://reviews.review-board.org/
Christian Hammond - chi...@chipx86.com
Review Board - http://www.review-board.org
VMware, Inc. - http://www.vmware.com