Please do not question me personally, this is just a rumor started in 2ch.net a japanese board.
Source: http://hissi.org/read.php/ff/20080717/eEJjNU5VbEIw.html
This link provide all the massages from the same user.
Here is what I try to translate:
The idea of going multi-plateform started at March 13th when the development team become the laughing stock when they only showen CG footage, only 野村 (sorry I don't know how to find his name in english translation) supported PS3 exclusive in the development team. Maybe versus will multi too (this is under wishfull thinking)
あのな~ お前らムチャクチャ言ってるけどPS3で開発すんの死ぬほど大変なんだよ
FF13もマルチにしなきゃ発売すら微妙だったのに
FF7なんか作ってる余裕があるわけねーだろ
Here it talks about the deficulting developing FF13 on PS3 and if this goes to exclusive it will not make profit.
Q isn't a lot of effort put into using Cell
A We found out it is a terrible hardware environment to develop
Q Since this is developed with PS3 in mind will multi-plateform represent fully?
A Yes, actually FF13 is developed under PC, it is actually easier to convert the game into 360 then PS3 (he also made a small comment if this was 360 exculsive it might even publish sooner)
Q Why not just remake FF7 rather then going multi
A We (Square-Enix) benefit more from going multi-plateform, even if we do FF7 it will probably going to be multi as well
Q Will the quality be degraded?
A Actually the quality on 360 will most likely be better and it will have more disc
We (Square-Enix) are not charity, if this does not make a profit it will make a great deal of trouble for the development team, 和田 (again sorry can't find translation) only made the sensible choise.
Below is some other random rumors from this poster
-Versus might turn into a movie instead of a game
-Microsoft paid full fee for the breach of exclusivety contract between SE and Sony
-SE will concerntrate on PSP rather then PS3 from now
-If SO4 can sell over 1.5M it will be xbox exclusive
-Last Ranment (sp?) exclusivety will be based on xbox sells
-There will be no PS3 Exclusive from now on
-There will be a FF13 Demo attacked to FF7ACC (rumor confirmed, was posted on 17/07/08)