Well, ok, not really - but I was able to deploy to the cloud and run my tester app against it - worked GREAT! Very fast, and no trouble (after I remembered to seed the test users and some bombs :)
One area I was somewhat worried about was the cron job, and the resources it will take. I am running it as quick as AppEngine lets me (once a minute). I am going to assume that if no records are returned it will have very little quote-impact. If not, I'll have to take a look at that.
I'm very interested over all what performance and usage will be once I get a bunch of users on this - and what it will do to the quota...
I have the cron job running now - I placed some bombs and they've all gone off (wiping out my tester users!), so I'll be able to see what that looks like in DB/CPU usage over night.
REALLY Glad to have gotten this far with the back end. I feel like I'm working well with AppEngine now, and OK with Python. I may be off on the GQL part of this (I think I may be doing too many refs), but am at least kinda getting the hang of it.
Wish I knew more Objective-C and had done more with the iPhone - only have a few hours of both at this point, so it's going to be a while before that part is done.