Great list of tips from Google developer advocate Reto, on future proofing your apps in the Android market
The aapt tip for dumping out what features your app requires was certainly new to me!
For anyone who is not aware or newer to Android, I always feel the need to highlight the Draw 9-patch technique as something that will help immensely when dealing with differing screensizes, and I am sure those that are using vanilla UIImage on iOS devices will come to envy in the future when supporting multiple screen sizes in an easy way that does not require code changes.
The following session video from Google IO on supporting multiple handsets almost goes into far too much detail and makes this problem space seem much harder than it actually is! However I and as am sure many, fully appreciate the highlighting of potential pitfalls that we may run into, rather than having to discover some of these hazards at some point through the development cycle of an application!
For those envious iPhone developers of NinePatch images you may wish to check out the following project http://blog.tortuga22.com/2010/05/31/announcing-tortuga-22-ninepatch/