Gingerbread on 39% of Android devices
2.2) which dropped from 51.2% to 45.3% and Eclair (2.0/2.1) which dropped from 13.3% to 11.7%. No real change in Cupcake or Donut, but at this point those devices aren't getting any updates. Honeycomb also saw a slight increase from 1.4% to 1.8%.
The trouble with these numbers is in the distribution of Gingerbread versions. The chart marks Android 2.3-2.3.2 at 0.5%, and then lumps together 2.3.3-2.3.7, which amounts to 38.2%. The trouble there is that while 2.3.3 marks the major bug fix of the random reboot on Gingerbread, the major feature update was 2.3.4, which added Google Talk video chat. We'd rather see 2.3.4+ broken off from the rest in the chart, so we can get a better read on how many devices have the video chat function.
source: Android Developers