I think a preseason football game should be regarded as slightly less significant than an intense day of practice.
Still, Tarvaris Jackson looked sharp in the Vikes' first preseason game. His mobility really gives the Vikings something extra to work with, and he's pretty accurate throwing on the move. He looks to have some chemistry with Bernard Berrian, who could be a really good player for the Vikings this year.
From Jackson, we'll be looking for smart decisions (limiting turnovers), accurate passing, and the ability to connect on deep passes. But he looks better than he looked last season.