I haven't seen Cars 2 (and won't), but the critical drubbing it took and Pixar's move into sequels has me wondering about the bigger picture.
Companies, like individuals, go through a life cycle. They grow, they mature and eventually they decline. The only difference between companies and individuals is that because companies can outlive individuals or change their personnel, they sometimes revive.
Growth is a phase where companies get larger but also expand their skills and discover their point of view. If we look at the Disney studio during Walt Disney's lifetime, we can see growth from 1923 to 1942. We can argue the exact dates or films, but the overall pattern is clear. During that time period, the skills and what exactly a Disney cartoon was supposed to be continued to evolve.
After Bambi, the studio was mature. A Disney cartoon was a particular, identifiable thing . When the studio deviated from that, in The Three Caballeros or Toot, Whistle, Plunk and Boom, it was imitating Tex Avery and UPA respectively. It wasn't breaking new ground, it was trying to stay current with other studios that were in growth mode.
For me, Disney's decline takes place when Woolie Reitherman was the sole director of the films. The narrative energy was dissipated, budgets were cramped, and there were significant amounts of re-used footage.
None of these stages is without variation. There are better and worse films in every stage and there's always room for differences of opinion. In broad terms, though, I think these descriptions work for Disney.
You can apply the same categories to individuals. If we take Chaplin as an example, his growth is roughly 1914-1917, the years at Keystone, Essanay and Mutual (where he perfected his art in shorts). His maturity is 1918 to 1940, the years of his best known features: The Kid, The Gold Rush, City Lights, Modern Times and The Great Dictator. His decline is 1947 to 1967, the years from Monsieur Verdoux to A Countess from Hong Kong. There are critics who find much valuable work in those later films and I agree with them, but there's no question that Chaplin's popularity was waning and that the films lack consistency.
Which brings us to Pixar. We now know what a Pixar film is like and what it isn't. That's a sign of a mature studio. The firing of various directors says that they were not capable of producing a Pixar film. We're also seeing less artistic growth. The preponderance of sequels proves that. What's going to be the ratio of sequels to original films? Two to one? Three to one?
The larger question is how long will Pixar's maturity last? Are the reviews of Cars 2 a sign that the studio is tipping into decline? If the film is a relative failure at the box office (acknowledging that the merchandising will more than make up for it), is that also an indication of decline? Did the studio actually reach maturity with Monsters, Inc. or Finding Nemo and it's maturity phase is now ending?
It may be too soon to get answers to these questions, but the pattern is inescapable. Disney revived and entered a new growth phase for a while in the years following The Great Mouse Detective. There's no reason that a declining Pixar couldn't revive as well, but it usually takes new management and a new creative team. There's no indication that's about to happen at Pixar, and it may be years before Pixar enters an indisputable decline. However, I sense that the studio is on the cusp and I'm curious to see if the next few films confirm my suspicions.