According to the latest report the most popular version of Android is new Jelly Bean. It overtook Gingerbread which now stands for about 34% of Android devices while Jelly Bean stands for 38%.
This news for developers means that it is time to switch from Android 2.x to Android 4.x. Maintaining 2.x mobile applications cost more because of little functionality and the age of the Gingerbread.
Still we are waiting for the version 4.3 and for the completely new version 5.0 of Android which hopefully will give more opportunities for Android developers and will simplify Android Development.