GoldenJoel from the forums noticed the following new screenshot over at GameSpy:
Initially there was some confusion as to whether this is new or not, because the third GTA IV trailer contains a scene which is very similar. However although it looks similar, it's not taken from the third trailer, and it is indeed a new screenshot.
Unfortunately it's pretty small, but we'll try to get our hands on a bigger version soon. Meanwhile, feel free to discuss it at the forums.