First, the update brings users the capabilities to use their own music in the background of the video highlight reel, and Sense will use the beat of the music to make picture changes. How cool is that? The latter is a feature of the HTC One mini that is coming to the full-sized model after the update. Other changes include a new Task Manager app and new short cuts to the data usage screen.
Remember that this is a pre-release build so there are some new things that will be coming to the official release. There is speculation that some new capabilities are coming to BlinkFeed, but again, that will have to wait for the official HTC rollout. In the meantime, if you are the gambling type, you can click on the sourcelink for the ROM.
Screenshots from the pre-release ROM containing the Android 4.3 update for the international HTC One
source: XDAdevelopersforum via AndroidCentral