If you're curious about what the next iteration of Google's mobile operating system holds, this video, which apparently shows off Android 4.3 running on a Nexus 4, should help. True, the focus here is on the interface changes and new features of the camera app, but the improvements are all positive ones.
The video, uploaded by a user named "cosminmkrk", does a decent job of exploring all the ins and outs of the updated UI. As Daniel Tyson over at Ausdroid notes, the full circle control has been replaced by a semi-circle one, so your finger no longer obscures some of the settings.
There's also a time-delay option, with a maximum setting of a minute, just in case you were having trouble with those more complicated selfies.
The post over at Ausdroid includes a few screenshots of the firmware and kernel versions, if you'd like to investigate further. There's also a thread on xda-developers discussing 4.3 more generally.