The Bengals might be the most underrated team in the league. They have always fielded a decent offense with Palmer at QB and Ocho at WR. Benson was, apparently, quite a pick up for them. It got their running game going. And their defense actually appears to be able to stop anyone.
Not excusing the Packers' horrible play in week 2, but the Bengals aren't last years Lions. They're closer to last years Miami. And Cedric Benson is a huge part of that.