I don't think that there is any update on this. We have only Moto's schedule of 1st quarter 2013 for Jelly Bean on the RAZR & RAZR Maxx. Since I have an SD card, I downloaded and installed the Dec 24 4.1.2 leak on Dec 25. It's very smooth. I haven't had any issues. I know that you stated in your earlier thread that you don't have an SD card, but they're not very expensive.
Mine is mostly smooth, but much more often than ICS, it will hang up in some random app or screen, and when finally getting back to the home screen after repeated pushes of the home button - the App icon will show up and it will take 3-8 seconds for the rest of the icons to show up again. Similarly, on a reboot the home screen takes 5-10 seconds for all the icons, favorites tiles, and battery widget to load. The alarm clock is a horrible piece of garbage, but not a huge deal. Disappointed that you can't get ro your contacts from the actual phone app. The Chrome app has a few plugins that I can't seem to get working. Other than that, it is pretty smooth and did add some quickness to it compared to the OTA ICS I was running.