Root works using @geohot kernel exploit. And when you root it you can use old bootloader exploit to unlock bootloader. Just unlocked my razr
After reading some comments I decided to add quick walkthrough (there are other ones inside this thread, so you're not obligated to use mine:
1. Get root exploit either from the original thread or from my dropbox.
2. You can also download bl unlocker motopocalypse.apk from my dropbox.
3. Put those files on your phone.
4. Install tr.apk and motopocalypse.apk
5. Run tr.apk, wait till it reboots your phone.
6. Check if root is working, if it does then run motopocalypse.
7. Check in fastboot more if "status code" equals "3" (turn off your phone and start it with power button + vol up pressed simultaneously).
8. If it does, you can appreciate @geohut and @djrbliss work by donating to them.