Google Android website tells us that more than 50% of all active Android devices accessing the Android Market are now based on the Android 2.3.x edition.
Around 35% of devices are still stuck on Android 2.2 edition.
2.4% of the devices are running the Honeycomb edition. Rest are on the much older builds of Android.
Android 4 was just announced last month and Galaxy Nexus is the first device to go on sale based on it.
Remains to be seen when the existing models on sale in the market would get the Ice Cream Sandwich update.
But it is pretty clear that a lot of devices would remain stuck on the 2.x editions of Android as only the most recent models would get the Android ICS update because of hefty hardware requirements.