Crytek have already said it cannot be done
Not quite :
" The engine right now is running on consoles so there’s no reason why we couldn’t "
" In order to make Crysis’s gameplay [on console] you would have to make a derivative Crysis and optimize it for the Xbox 360 and PS3. In fact, if we do it, we’ll optimize it for each platform "
http://www.gameinformer.com/News/Story/200710/N07.1004.1210.04388.htm?Page=2