Geez guys!
I just can't get enough of Toy Story, whether it's the shorts or a whole new feature. They could have a lot of fun new adventures with Bonnie, maybe they'll try to track down Bo Peep, or maybe accidentally fall into the hands of a customizer? Who knows, but I've loved every TS movie, and that's Pixars' baby, so I know any further ventures will be handled well. Yes, TS3 completed the story... with Andy, but the toys still have a lot of story to tell!
I'm reminded of Scrubs.
Now, if anyone remembers, NBC planned on cancelling the show, but a writer's strike prevented the creators from giving the show a formal send off. ABC comes to the rescue and brings back the show for one more glorious season. The show had a beautiful, heartfelt ending... a true ride into the sunset.
Then they brought it back for another season. And it was the most low rated, unwatchable, forgettable season there ever was. Instead of fading away into the sunset beautifully, it pulled a Daffy Duck, ran back out on stage and danced around pathetically until the long cane came by and pulled them back in, not even kicking and screaming loudly.
All good things have to come to an end, eventually. Jim and company felt 5 seasons was enough for the Muppet Show, Fraggles left television on the highest possible note when HBO was threatening to reformat it as a preschool show.
To me, Toy Story three ended on the highest possible note. A glorious, heartfelt, tear welling, beautiful goodbye. Sure, I can see more short segments, some comic book continuations... maybe a holiday special. But a fourth movie would be pushing it, no matter HOW good the story is. It would further blur the lines between them and Dreamworks (their next batch of films don't sound half as good as their last few), and we don't want to see that happen. Pixar makes animated movies kids like that, if filmed in live action, could be considered art house films. Up was praised for having raw emotions other movies just don't have anymore (even those lame Oscar Bait cryfests, which come off mechanical). Cars 2 was a nice break from that, but I'm drooling over Brave. I wouldn't doubt another Cars would be made, but another TS is just too much.