Nearly Half of All Android Devices Have Jumped to Jelly Bean
That means that the vast majority of Android users, including those on Jelly Bean, are missing out on the latest features, some of which include virtual surround sound, OpenGL ES 3.0 and the various optimizations that make Android run faster, autocomplete on the dial pad, location detection through Wi-Fi without turning on Wi-Fi all the time, restricted profiles, and a few other tidbits.
Interesting, the second most used version of Android is Gingerbread (Android 2.3.3 to 2.3.7), which is now several generations old. The reason is because there are still a lot of lower end devices being sold, as well as dated smartphones that have long been forgotten by their manufacturer and wireless carrier.
Looking ahead, the next major release of Android is KitKat (Android 4.4), or the operating system previously known as Key Lime Pie. KitKat is rumored to launch later this month with support for wireless NFC payments, Miracast, a redesigned camera UI, and more.