Duckandcover has a batch of Fallout: New Vegas screen shots.
Visually, it looks about the same as Fallout 3 from what I can tell, but there is a good amount to look at in terms of content. There is a giant T-rex made of stone. That is enough for me.
You can check out the screen shots over in their gallery.
Fallout: New Vegas is scheduled to hit this Fall.