Hi, Constantine
Short answer: It can work. Probably.
Long answer:
One way to do it is to start with a pyramid scaffold newly built just
for this purpose.
http://pypi.python.org/pypi/pyramid_appengine/0.5.2dev
Note the "dev". Help development of this scaffold by submitting issues
to https://github.com/twillis/pyramid_appengine .
BTW, An initial proof of concept of the setup you mention (and using the
scaffold I mention) is at http://test-app-509.appspot.com/ .
- Jim Washington