Personally I just consider every Pixar movie a sequel to the previous Pixar movie. I treat Pixar more like a director or author. The stuff may be different but I'm going to buy the next Neil Stephenson novel even if it's a cook book.
That was kind of my point. Pixar or Dreamworks or Disney Animation or Illumination as a brand are bigger draws than being a sequel. "I want to go see the new Pixar movie."