Redmine's a pain to install but pretty great once up. It has a very good plugin model through which we can add anything we need. Rob Lanphier and I discussed this a few times and came to the conclusion that Redmine + helping upstream fixes to plugins like
http://www.redminebacklogs.net/ should cover all our use cases. We even have a migration path from Bugzilla as we can import all the historical data, even preserving bug numbers:
https://github.com/ralli/bz2redmine
So if anyone decides to tackle this beast, count me in. The test redmine instance is back up (I think it goes down when the machine restarts - this is just my configuration mistake surely)