According to Heavy.com:
Very strong rumors are circulating from the West Coast that UFC middleweight Demian Maia (12-1) has been chosen as the replacement for the injured Vitor Belfort and will face Anderson Silva for the UFC middleweight title at UFC 112 in Abu Dhabi.
Sources close to the fight say the bout has been verbally agreed and will be signed shortly.
Update (by Kid Nate): I have to be skeptical that this match will happen but if it does it'll be because Abu Dhabi has no athletic commission. From the medical suspensions after UFC 109, via MMA Mania:
Demian Maia: Suspended until Aug. 6 (eyelid laceration) unless cleared early by an ophthalmologist or ocular-plastics doctor
Update (by Kid Nate): Well I'm eating my crow fresh tonight. From UFC.com:
"It’s always tough when a top fighter like Vitor Belfort has to pull out of a big title fight, but we have found a high quality replacement," said UFC President Dana White. "Top contender Chael Sonnen was not available due to injuries sustained in his fight with Nate Marquardt, so top six middleweight Demian Maia will step in to fight for the title. Maia is an Abu Dhabi grappling champion, a five-time Brazilian Jiu-Jitsu world champion, and he is 12-1 in MMA and coming off a win over Dan Miller at UFC 109. Anderson Silva vs Demian Maia will be a matchup between MMA’s best striker and MMA’s best grappler."
Unless Maia is cleared by a reputable medical specialist, I have to strongly disapprove of the UFC's decision to book a seriously injured fighter for a fight in a venue with no athletic commission.