According to VG247, both railers for both God of War 3 and Uncharted 2: Among Thieves are going up on the PSN on Thursday, January 22.  While it wasn't specified whether the trailers would be new or not, all the trailers currently out for both games are already available on PSN, so that would point to them being new.

Both Sony exclusives are due out in the later part of 2009.