I think it's highly unlikely that the PS4 would be released anytime before 2013 given that the PS3 is still in its prime. As for the FFVII remake, if they are considering making one then it would probably come out for the 20th anniversary of FFVII (which would be in 2017). To remake the game from scratch would take several years and at present they are still working on way too many projects to have the freedom to do so.