I've taken most of this work and merged it into a new project called Gaengo, a cut-down version of django for use on GAE. I'll document what I've done later on, but for there's:
- Django now uses the Mail API
- BigTable Cache Backend
- BigTable+LocMem Hybrid Cache Backend
- list_detail generic views work AFAIK (needs more testing)
- Signalized versions of the Datastore Model/Expando for use with dispatcher (pre/post init, pre/post put, and pre/post delete signals are thrown for the master classes and each subclass)
More to come. Keep watch on
http://code.google.com/p/gaengo/ where the project is hosted.