Some Italian tard has gone and smuggled out some footage of a GDC presentation about Uncharted 2 and posted it on their website. The video shows that Naughty Dog have definitely upped the ante on this one and the increased difficulty and range of climbing is immediately obvious.
The better quality video can be found here, but if you want there is a crappy version after the break.
Update: The Italian site has pulled the video (surprised?).