Actually mattlgroff "cheesecaked" a leaked build (not the OTA) off of Moto's servers. He had to be rooted to do that obviously, but the build will flash on a stock/retail/unrooted Razr M.
A fastboot file was also released that will supposedly get you back to stock ICS - but I have yet to see anyone do it, myself included.
Thanks to some instructions from Matt (mainly due to the fear of being stuck on this leaked build forever, and how to potentially avoid that), I felt more comfortable flashing the leak today, been running it since mid-afternoon.
I intended to write up a bit more about it over in the "leak thread", but just haven't had a chance. So far, I don't see any glaring errors. JB runs great on it. It's a little smoother/snapper, not quite as drastic as the change when the Gnex hit JB, but still good.
Leak thread here on DF (that I need to update!): [DO NOT TRY] Razr M Jelly Bean Test Build
XDA thread with great info from Matt: http://forum.xda-developers.com/show....php?t=1934396
XDA thread with fastboot: [Fastboot] Droid Razr M Xt907 Ice Cream Sandwich - xda-developers