I finally bit the bullet and saw it today. I felt obligated to do so, as I haven't missed a Pixar film in theaters yet. I didn't think the movie was as bad as everyone said, but it's still Pixar's worst. I don't know if I even want to buy it on DVD, let alone Blu-ray. It didn't even feel like a Pixar movie. However, the visuals were impressive, especially the London scenes. It looked photorealistic.
Mater wasn't as annoying as I thought he'd be, but I just gave even less of a crap about him than the first film. Same for McQueen. The only new characters I really liked were because of their voice actors. McMissile (because it was Michael Caine), the jet (Jason Isaacs) and the American spy (Bruce Campbell). In fact, the only returning characters I liked were Guido and Luigi. They're probably the best characters in these movies.
On another note, the Toy Story short before it was worth the price of admission. That was delightful. Cars 2 was just the storm we had to drive through to get to Brave, which looks really promising.