Pixar and Disney currently have an agreement where Pixar is responsible for content and Disney is responsible for distribution and marketing. But today, Pixar broke off 10 months of negotations over the future of the Pixar/Disney relationship, saying that Disney unfairly wanted too much of the profits.

From this article at CNN:

"After ten months of trying to strike a deal with Disney, we're moving on," Pixar CEO Steve Jobs said in a statement. "We've had a great run together -- one of the most successful in Hollywood history -- and it's a shame that Disney won't be participating in Pixar's future successes."