This game might has chance to sell 10 million but not as much as FFVII. I believe FFVII had sold 12 million across PS1, PSN and PC. FF series is not as popular during FFVII and FFX but everything can happen in future. FFXIII might revive the series like COD4:MW did for COD series.
My prediction
Low end
PS3 - 5.0 million
X360 - 2.5 million
High end
PS3 - 7.0 million
X360 - 4.0 million







