Today's dashboard's data is accurate up to three days ago, and provides insight into the mix of Android devices out in the wild.
As you can see, Android versions 1.5 and 1.6 comprise the vast majority of Android installations at present, nearly 82%. Devices presently running 2.0.1 make up just under 15%.
While this is a handy tool for developers to single out the version for which they should develop, it is also somewhat useful for gauging the penetration of the various Android devices. The Droid Eris by HTC and Cliq by Motorola, for example, are both based on 1.5, while the HTC/T-mobile G1 and MyTouch3G run 1.6. The Motorola Droid, which is the only Android device officially running version 2.0.1, therefore makes up 15% of the Android population by itself.
This data is, of course, only so accurate. It is gathered from Android devices that have accessed Android Market within a 14-day period ending on the data collection date (Monday). So if an Android user did not access the market in the last two weeks, his device was not counted. Furthermore, there is no way of knowing which device is running which version, so it is possible that more people have rooted their phones and installed different versions, instead of leaving them with the manufacturer-sanctioned OS version.