It would certainly help, no question. I'm sure they'll support it soon. Django's honestly tough to beat, though, and GAE's tools for updating your app and viewing your logs and traffic are pretty sweet.
Google's mostly a Java and Python shop, so I'd guess they'll support Java before RoR and PHP.
Your characterization of New York is very much that of a visitor, as it should be. "You should be richer" is not the defining characteristic of New York, it's "you're a minority." For anyone who has lived here for a year or more, the fact that everyone is a minority on some level is what makes New York breathtaking.
The New York you're talking about is also a minority. From the outside, Wall Street and Madison Avenue may seem to dominate. From the inside, they're barely noticeable unless you're in that world. Wall Street and Madison Avenue are swept up in the endless current of people just like the gay Puerto Rican teens who hang out above Pier 40 on Friday nights in the summer.
The depth and breadth of "New York" is what makes it truly great. New York has so many worlds swirling around you that you'll never fully understand -- it's humbling and exhilarating to the core. New York's "ambition" is the endless hope of all of those minorities from countless directions -- the ambition you're talking about is much more one dimensional.
Google's mostly a Java and Python shop, so I'd guess they'll support Java before RoR and PHP.