except a bunch of no-name Ukrainians did exactly that with Metro 2033, and it looked as good as if not better than Crysis at times.
Metro 2033 is mostly small corridors hence you can spend more resources on the nearby walls and effects, while crysis was rendering entire panoramic views of an island. Additionally Crysis released in 2007 and Metro 2033 was released only last year, if anything Metro 2033 should look as good as if not better than Crysis all the time if not they haven't improved on something that came out almost 4 years ago.
Regardless of this my statement was that consoles are holding back development in games and they are, if you compare the 360 version of Metro 2033 to the PC version you will see the difference.
http://i38.photobucket.com/albums/e110/b20vteg/metro%20comparison/metro_2033_vgl7.jpg