Pythonista should eventually move over to Python 3. It has improved syntax, new features, and is the current standard. Python 2.7 will be phased out eventually. The only technical reason you mentioned, that lack of PIL on Python 3, is not much of a reason at all. PIL is essentially obsolete now. The Python community is largely moving to better maintained backwards compatible forks of PIL, such as Pillow, which has more features, fewer bugs, and is fully compatible with Python 3.
With that said, there is no urgency in moving Pythonista over to Python 3. I would welcome two separate versions of Pythonista for Python 2 and Python 3, but it isn't really necessary yet.
What I would really appreciate soon is a new version of Pythonista that includes Python 2.7.5 and is compatible with iOS 7. There are many bugs that significantly impair the usability of Pythonista on iOS 7, and roughly 3/4 of all iOS users are running iOS 7 now. If funding is an issue (though it doesn't seem to be), I and likely many other Pythonista users would be willing to help out.