Android Police posted a story that Google is working on Android 4.3

As everyone is trying to guess whether the next big Android update is going to be Key Lime Pie or not, and whether the release will be Android 5.X or 4.X, we have yet to hear anything concrete. After getting a tip from an eagle-eyed reader (thanks, deepayan!) and digging deeper, I can definitively tell you that Google is currently working on Android 4.3, and it is still Jelly Bean.

  Google Is Working On And Testing Android 4.3