Google has been posting all of its Google I/O sessions online for all to view. This should prove helpful if you did not attend, or if you did attend, and want to playback certain parts again.
Either way, if App Engine is your thing, you should take note that these five videos are available to view.
First, here is an App Engine overview:
This one is about HTML5 and App Engine. The description says:
This talk discusses the latest and greatest application patterns and toolset for building cutting edge HTML5 applications that are backed by App Engine. This makes it incredibly easy to write an app that spans client and server; in particular, authentication just works out of the box. This talk walks through building a fantastic cloud-based HTML5 application.
This one is about building mobile app engine backends for Android, as well as for iOS and the web:
This one is about getting the most out of Python 2.7 on App Engine:
Finally, this one shows how to use the Maps API and Go on APp Engine to build an app to build custom tile sets for Google Maps: