Android 4.3 being tested for Samsung GALAXY Note II; expect late 2013 release
There is also speculation that the Samsung Galaxy Mega 6.3 and Samsung Galaxy Mega 5.8 will both be on the receiving end of the Android 4.3 update. If you're looking for a device already running that build, there is the Samsung Galaxy S4 Google Play Edition, the Samsung Galaxy Note 3, the Google Nexus 7 (2013) and the Google Nexus 10.
We all know that the next Android build will be Android 4.4 KitKat. The first Android device to offer that chocolatey goodness should be the rumored Google Nexus 5. This device is expected to be launched in October with KitKat installed right out of the box.
source: SamMobile via AndroidAuthority