Anyone who wants to party with this beta release could do so by downloading 
http://su.barnesandnoble.com/nook/pi....10/update.zip  and doing the usual copy update.zip in over USB.
For some reason, I think this was only sent to 4 devices.  I can't imagine why?
This release doesn't appear to break any of the useful legacy capabilities from GLP days - but having a good way to downgrade would be recommended.