As far as i no the new liteon-83850c,are only being sent back from microsoft,on some repaired consoles,i found this from Team HyperX, which is of corse good
news,as they dont mess around.....
quote-
The LiteOn revision 83850c that has been mainly coming out of repair centers in europe has been fully dumped. More details will come as the firmware is fully decrypted, but at the very worst we have a work-around if all known backdoors are disabled. A solution for this model will NOT be released to public until this version becomes mainstream. E.g. is being shipped commercially with new xbox360's.