The ‘Big G’ has just pushed all the source of Android 2.3 to the Android Open Source Project, meaning that anyone can now build Custom ROMs (and Manufacturers can now build for official ROMs) for devices. If you have a rooted device, you’ll no doubt see countless numbers of Android 2.3 ROMs pop up for your device. Exciting!
Along with the source Google has released the Android Compatibility Definition Document, which is all the standards a device needs in order to run Gingerbread properly. There are a few interesting things in it, such as devices SHOULD have a Gyroscope. You can check it all out here: http://static.googleusercontent.com/external_content/untrusted_dlcp/source.android.com/en//compatibility/android-2.3-cdd.pdf