The AOKP team has been lagging behind compared to other custom ROMs in releasing an Android 4.3 based ROM for their followers. The team provided a status update a few days ago confirming that they are working on AOKP 4.3, and should push out nightlies for selected devices soon.
Today, the AOKP team has started rolling out preview build of AOKP based on Android 4.3 Jelly Bean for a selected devices. Right now, the team has released the builds for the various variants of the Galaxy S4 including T-Mobile, US Cellular, and Verizon. The builds for the said devices can be downloaded from here.
Owners of 2012 Nexus 7 owners (without 3G/grouper) can download a test build of AOKP from here. For other devices, I will recommend readers to head over to their respective thread on XDA or Rootzwiki forums for the download link. Keep in mind that since this is a preview build, some features will be broken, others missing and some will function as intended.
If you do end up flashing AOKP ROM on your Android device, don’t forget to submit bug reports to the AOKP team so that they can squash those bugs.