I'd be a lot more comfortable with more Toy Story films if they started with a brand new cast of toys. The trilogy ended so perfectly; let the story of Woody, Buzz and the others be done. It took place over the span of 15 years: enough time for the original audience to start elementary school, finish college and start families of their own! Let my generation have our trilogy intact and untainted, and let this new generation have their own cast of memorable characters that they can grow up with.
Also, did anyone notice how the first film begins with a shot of clouds in the sky, and the third film ends with a similar shot? I felt like that was the director telling us that the story really was over for these guys, and that we had seen all we needed to see.
