Cars 2 is indeed terrible. It's sophomoric, needlessly convoluted, senselessly violent, and pretty much negates everything that people liked about the first Cars. But even with all of those things being true, Pixar will be fine. It's one movie, something that John Lasseter really wanted to do. And while no one will call it a bomb, it will likely be one of Pixar's lowest grossers ever and a rare critical whiff. But Pixar will be fine. They will have three sequels nearly in a row between 2010 and 2013. That's partially due to the original Disney contract, which demanded five original films (hence they held off on sequels until they took over Disney animation). But Pixar will be fine. And so will you, moviegoer and fan. They just have to keep moving forward...
Scott Mendelson