FFXIII's development started for PS2 and later moved to PS3.
While I was watching the ending ingame scene from the 13th December FF13 trailer. I've noticed that some part of the ingame were very bad compared to the screens from IGN. In My opinion this could easily run on the PS2 and the footage at the end of this trailer could be the PS2 version. This is a comparison:
Lightning Ingame On PS2:

By
mercy0001 at 2009-01-21

By
mercy0001 at 2009-01-21
Lightning Ingame On PS3:

By
mercy0001 at 2009-01-21

By
mercy0001 at 2009-01-21
The Soldiers Ingame on PS2:

By
mercy0001 at 2009-01-21
The Soldiers Ingame on PS3:

By
mercy0001 at 2009-01-21
Lightning And Vanille on PS2:

By
Mercy0001 at 2009-01-21
Lightning And Vanille on PS3:

By
mercy0001 at 2009-01-21
And the last comparison is the best. You can really see that the first image isn't PS3! Look at Snow!
Lightning and Snow on PS2:

By
mercy0001 at 2009-01-21
Lightning and Snow on PS3:

By
mercy0001 at 2009-01-21
What do you think?