Well it seems plausible now bionics with the leaked 5.7.893 update can now get back to stock. Afterwards they then can install the 5.5.893 OTA and the new .901
Information is in this thread: Getting back on the OTA update path - RootzWiki few people are claiming success. I haven't tried this. I have been following this thread for the last few hours waiting for others to claim that it is sucessful.
Steps it seems to me is:
1. Restore back to .886 then option 1 to forever root.
2. Install the original stock modem in stock recovery http://dl.dropbox.com/u/21566851/Phone/radio.zip
3. While rooted and usb debugging on, install this http://dl.dropbox.com/u/54323236/5T0ck886.rar
After step 3 some people could no longer boot and then did step 1 again
4. The 5.5.893 OTA would now install successfully