It seems that, IMO, if there was not so much concern about "regressions" in releases, this whole revisit-versioning debate would not have come up. This implies, to me at least, that the root cause (as I've said before) appears to be one related to QA and testing more than anything. Unless we address this, then nothing else really matters.
We have a test framework. The questions are:
1. Are we using it?
2. Are we using it sufficiently well?
3. If not, what can we do to improve that?
4. Can we supplement/replace it w/ other frameworks?
It does seem to me that each time we patch something, there should be a test added or extended which covers that bug. We have gotten lax in that. Same for features. And the more substantial the change (ie, the more core code it touches, or the more it refactors something), the more we should envision what tests can be in place which ensure nothing breaks.
In other words: nothing backported unless it also involves some changes to the Perl test framework or some pretty convincing reasons why it's not required.