When it comes to naming the different Android versions, Google has certainly taken a delicious route and it looks like they are working on the final version of Android 4.2.2 Jelly Bean before rolling out the much-anticipated Android 5.0 Key Lime Pie in May this year (2013). Currently, the update is undergoing internal testing according to IBTimes, and Google has not pushed this update to Android Open Source Project (AOSP) and neither has it confirmed when users will get it on their devices.
The Android 4.2 OS was unveiled by Google in October last year and it has some amazing features such as Gesture typing, Photo Sphere among other features. The Android 4.2.1 update was rolled out in November last year fixing a few bug issues.
The 4.2.2 update is said to provide minor bug fixes and performance enhancements to the OS without necessarily making significant changes to the user experience or interface.
It should be noted that at the moment, 45.6 % of Android devices run on Android 2.3 Ginger Bread compared to 1.2 % that run on Android 4.2 Jelly Bean.