It's a big ol' slice of nostalgia. A lot of it you won't really get if you didn't grow up with the Muppet Show and the movies, but from the sound of it that didn't bother the kids in the audience, for whom the general mayhem was enough. As a bonus, you also get a fun new Toy Story short (if only Happy Meal toys were really that creative. I kinda want a DJ Blue J).
Trailers for Pixar's Brave (story seems a bit cliché, but the visuals look lovely) and Aardman Animation's next stop-motion feature, about pirates, which looks hilariously madcap.