The Android emulator doesn't come with a way to control the pitch, roll and other sensor controls, which makes testing on anything other than real hardware difficult.

Google fixes this with the SensorSimulator here: http://code.google.com/p/openintents/wiki/SensorSimulator

I particularly like the way you can set the gravity value, for example when testing your applications work correctly on other planets. Now thats what I call future proofing!