I saw it. It's not terrible, but it's not very good either. Definitely Pixar's worst movie thus far and the only one i'd not consider at least good. I wouldn't say it's worthy of anything less than a 5/10, but it's not worthy of anything past a 6-7 either. I'd probably give it a 6/10. It's just mediocre. I didn't hate it. It had some funny and cool scenes and i've definitely seen infinitely worse animated movies (some of which got praised way too much imo).
Worst issues i have is that the dialog is bland for the most part besides from some jokes here and there. The story is disjointed and feels hastily smashed together. Multiple plotlines, all of which feel underdeveloped. There was a lot of potential for a spy car theme or even a world grand prix race. None of it felt well written or developed. Characters too were bland and uninteresting. They also tried to tack on an obnoxious environmental theme. I hated that, this coming from an enviro-hippy of sorts myself. It was done RIGHT in Wall E (one of the few environmental statement movies that did it right), dead wrong here. The one thing i really enjoyed in the movie was Mater. And considering he's widely hated by many people, i'm sure i'm in a minority.
But shit happens. If anything i'd say that an animation studio having 11/12 movies that are at the very least what i'd consider GOOD (yes even Cars 1) is a good sign. No movie studios is perfect and will inevitably make a movie that isn't so good. If the next two Pixar movies in a row are bleh, i'll definitely say something is up, but they've fluctuated in quality before. As i recall, Cars 1 wasn't very well received either (not bad, just average to decent review, i liked it personally). But then the 4 Pixar movies afterwards were incredibly well received, all garnering Oscar nominations (a couple even being nominated for best picture).
@AlanJohn-
Pixar is working on a Monsters Inc prequel entitled (working title anyways) Monsters University. Apparently showing how Mike and Sully became friends and graduated from college or some shit-
http://en.wikipedia.org/wiki/Monsters_University#Prequel
I'm more interested in next year's Pixar movie, Brave. Original fairy tale, looks interesting and a nice change of pace from Pixar's usual stuff.