It seems like they've been all over the place in terms of intended platforms. Some journos at PAX said they would not commit to specific platforms when asked point blank, but the official videos have big PS3 and 360 logos on them. After the Japanese presentation it was being reported that they had confirmed PS3/360 and PC, but no one seems to be able to pin them down any more. IIRC when the Fox Engine was originally debuted (in the infamous Transfarring video) Kojima said all his future Fox Engine games would be cross-platform for PS3, 360, PC and Vita.