OTOH, webapp2 was incorporated into the platform. There are a lot of interesting things you can do under app engine and, maybe, platforms as monolithic as Django have a hard time living on Google's platform.
And note that the author abandoned Tipfy for it.
The only thing I miss when using Django on EC2 is the automagic zero-admin scaling Google provides. The only thing I miss from Django when using App Engine is the admin (which wouldn't work on top of the datastore anyway)
It does, though, it works fine with django-nonrel.