Thanks for the work on 3.1! I noticed the GAE compatibility note in the latest release notes. I was just about to give this a try again with the 3.1-final. Another showstopper I hit was that sessions crash, even when setting the type to 'ram'. So I think having a "gae" session type will be a must-have. I'll try hacking on that a bit if I can.
CherryPy 3.1