A big part of Google's presentation today centered around Android 4.3 We've already mentioned that the New Nexus 7, which Google by the way calls the Nexus 7 2013, will come with Android 4.3 pre-installed. Nexus 7 2012 (that's the original 1st generation) owners should be seeing Android 4.3 pushing out to their devices starting today via an OTA update. Now those that don't want to wait or want to install manually can also get the files via the AOSP (Android Open Source Project). You can download the files here.
So what is new with Android 4.3? Well to be honest a lot of the improvements are behind the scene and will make your tablet runs faster and smoother. Some of the cool noticeable additions that you will notice however includes: Restricted Profiles
The new Restricted Profiles feature is perfect for situations where you want to limit a particular user's permissions and/or access to certain features of your Android device. This is great of course for parents as you can lock down your device and completely control what apps and files your child will have access to. Apps also will hide certain features or options depending on the profile's restrictions. For instance if you don't want your child to be able to purchase new levels of a game, any payment required levels will be hidden so the child won't have the option. Bluetooth Smart Support
This enables your device to connect to a whole new range of mobile apps that connect to fitness sensors. OpenGL ES 3.0
Ratcheting up the graphics bar, OpenGL ES 3.0 gives faster, more detailed graphics in your gaming and apps than ever before. Virtual Surround Sound
In supporting devices like the New Nexus 7 (2013) virtual surround sound is provided via Fraunhofer Cingo mobile audio technology.
There's actually a bunch more features including added language support, Dial Pad, Location, new Settings, System and Networking that you can read about on Google's Android 4.3 Jellybean info page