Anyway, this is all theoretical (in the worst sense of the word) - the app is not even public.
I initially fell in love with the "no sysadmin" aspect of App Engine, and started building apps around it. Eventually I realized that (for me, anyway) the upside isn't really worth the trouble of having to contort my apps to work in Google's sandbox- can't run SQL, have to deal with datastore timeouts, CPU timeouts, etc. When you're done coding work-arounds for all of these things, are you really coming out ahead?
Also the way Google handling this confirms my fear of proprietary lock-in, leaving a really bad taste in mouth. I meant I've spent lots of time to develop in their framework to work around their quirks and limitation. They have been advocating to developers to optimize for CPU time and that's what we did. Now they found out they don't make enough money with CPU optimization and change the whole billing scheme, screwing all the efforts done by developers. What would stop them to change again tomorrow if they find instance-hour is not making enough money for them?
Ultimately, after a lengthy debate with a friend, I concluded that Heroku was a sufficiently better option that it was worth learning Ruby (which I've been writing more or less as an uglier Python anyway).