So I've been talking about a railish routing scheme for GAE. Finally after nibbling on the problem whenever I could score some free time, I've got something that's working (if not perfect) here - railsish_gae.
In short, it's a mechanism for automagically loading up a controller, executing an action, and rendering a template based on the URL that was called.
Dunno if it'll be useful to anyone else, but I'm just glad I can quit OCD'ing on this relatively small problem. :)