If you get the M logo and you have a backup.
Pull your battery and place it back in after 5 seconds or so (so the phone is completely off)
while off plug your phone into the wall charger.
Then turn your phone on. If you get the charging screen press power again (I tried this and I actually had to hold the power button a little and it did not work the first time).
now you should be in clockwork recovery so you can do a restore if you made a backup.
If you can get into clockwork you can mount your sd card to put a stock rom on it.
method from newk8600 of xda