Google slips TRIM support into Android 4.3 to end I/O lag
Google made a lot of small tweaks to the way Android works with version 4.3, which has only hit the unlocked Nexus devices so far. There is the new OpenGL ES 3.0 support, restricted profiles, a notification handler, and various other bits and pieces.
Nexus 4, Nexus 7 Android 4.3 Updates Hitting More Users
Android 4.3 – New Features and Improvements
Android 4.3 Nexus 4 update released in UK