Assuming Pac16 forms -
Pac16 - CU/Ok/OkSt/A&M/TTech/Texas
Big10 - Nebraska.
Big12 - KState/Kansas/Missouri/Iowa State/Baylor (5 teams)
Cinci/BYU/Utah/TCU would have been the first added, possibly add in Boise/CSU/SDSU or some other schools to get back to 12.
UCF is not considered in 2010
Missouri (and Kansas) would want out, I don't know if they will get out but additional teams need to be added to get back to 12.