Jelly Bean rises as Ice Cream Sandwich falls, legacy versions remain virtually unchanged
Google has released the platform version numbers for the month of April, and the general trends we've seen for the past months is still the norm. Jelly Bean is slowly growing, up to 28.4-percent compared to last month's 25-percent. The majority of the growth looks to be coming from devices released with Ice Cream Sandwich, who's numbers have dropped almost two-percent as devices get updated. Honeycomb is also declining, as is Gingerbread. Legacy numbers are pretty stagnant, and any movement there is likely from users upgrading to a newer device.
The important number, from an application developer's point of view, is that over 50-percent of all devices now run Android 4.0 or higher. This number has to move higher, and faster than it has been, before they can stop writing apps designed to work with older devices. The good news is that device manufacturers seem to be targeting the latest versions with new hardware releases, so there may come a day when everyone can stop worrying about Gingerbread.
Source: Android developers