The code refactoring is now done for importlib. Now I am trying to make it pass Python's entire regression test suite as the import implementation. This has led to the discovery that runpy (the module that implements the '-m' command-line option) wants loaders to be stateless. That kind of sucks as that will spike the amount of stat calls I will need to make, but that's life when you are dealing with a filesystem and you don't assume its immutable. =)
And I have now been given the task of getting importlib into Py3K. I won't make a1, but since I am not introducing new features that is not an issue. But I need to get the 2.6 version squared away first.