New figures on the OS composition of Android devices accessing the Android Market gathered by Android Developers shows that devices running Android 2.1 now make up 55.5% of all devices. The rise in Android 2.1 adoption is no doubt due to the updates that are being pushed out to devices, and the release of so many new handsets running Android 2.1.
AndroidGuys observes after looking at the whole chart that "we still have fragmentation(or legacy as they call it), but Android 2.1 is shaping up to be the platform starting point for developers and hopefully that will lead to much better apps.
Gizmodo notes that "Android 1.5 is still going strong, too, thanks to the slow pace of updates around the world and a few phones left in permanent limbo by their uncaring makers."
I think that most of those figures will be Nexus One handsets, but some of those are probably people running custom ROMs because the can't wait for their carrier to push out the Android 2.2 update.
Image from Android Developers