The main tool of thunderbird-drivers is a rough prioritization of bugs done with a couple of flags:
; Blocking: a bug that, if it were the last unfixed bug, we would hold a release for, rather than ship without. Note that this implies that fixing the bug is worth the time-value of not having the rest of the release in hands of end-users for that much longer.
; Wanted: a restricted set of things that thunderbird-drivers think would be nice to have, but that we would be willing to ship without. Note that wanted- doesn't mean that we wouldn't accept a patch; it means that we're not actively devoting any energy in trying to get this into Thunderbird 3.