[people ask assorted hypothetical questions about backporting]
Note that if the PBF is a success (and I sure hope that it is!), backporting stuff to the py-in-a-tie release line is supposed to become its job, not Python-Dev's. They'll backport whatever they see fit, and it won't matter what even Guido thinks then.
In the meantime, I suggest *we* stick to backporting unarguable bugfixes. How can you tell whether something is unarguable? If in doubt, backport it, and if someone complains, tell them to revert it <0.8 wink>.