Been playing with this lately. The framework Google provides to access their app engine service is written in python and largely Django from what I can see.
You can supposedly run whatever you want on top of it that uses WSGI with some modifications.
I think I may give this pylons a try at the same time with appengine-monkey . I fear that may be enough steps when using a new framework that idea may be doa but we'll see how much time I have over the next couple of days.