Do not do this, I repeat, do not do this... there, you've been warned.
mattlgroff cheesecaked this off of Moto's servers...
As he says:
"It will install on retail devices but there is not a good chance of returning back to stock ICS without retail Verizon fastboot files."
So, unless you want to potentially be stuck forever on this build, and this is no joke, don't do this. This is a test build, and by no means final. But it's good to see the builds out there, nonetheless - which is the main reason I'm passing the info on over here.
Here's the thread at XDA with links:
Did I mention not to do this?
Sure, we could see fastboot files at some point... but who knows how long? And what if they don't work on this build?
The M, RMHD, and RHD are supposed to get Jelly Bean by the end of the year anyway - the official, final version - NOT this version.