But it makes me wonder why Google hasn't done this on their own yet. Maybe because they're trying to re-create every possible web app so you don't need to login to anything but Google?
scratches head Couldn't you have done this before using AuthSub and a registered application?
The only thing that seems different is that Google returns an email address to you with App Engine, so you can skip that step in the registartion process.
But it makes me wonder why Google hasn't done this on their own yet. Maybe because they're trying to re-create every possible web app so you don't need to login to anything but Google?