I just got back from Monsters University, and I thought I'd share my thoughts. (No spoilers)

It's not quite as good as the first one, but it's close enough that you should still go see it. The monster designs, jokes, and a lot of what made the first movie good are still intact, though without Boo it does feel like it loses a little heart (despite the film trying desperately to fill that gap with some new characters), and it is a much lower stakes film, not that there's anything inherently wrong with that.

It's funny. It had me laughing out loud quite a lot.

Even though it's a prequel, it managed to actually surprise me with where the plot was going a few times. I thought I had it figured out multiple times, only for things to take a turn I didn't expect, for the better. That's pretty rare for a prequel, so kudos.

It's not Pixar's best work (The Toy Story trilogy, The Incredibles, Up, etc.), but it's far from it's worst (Cars, Brave, and though people will probably skin me alive for it, Wall-E). It feels like a return to form for Pixar after their last couple of films were disappointing. This feels like a Pixar movie again.

Best college-comedy for kids since An Extremely Goofy Movie! (Only college-comedy for kids since An Extremely Goofy Movie.)

Trailers:
Despicable Me 2, looks awesome.
Frozen, no idea what it's about, the trailer was a decent teaser, with "the creators of Tangled and Wreck-It Ralph" behind it, it'll probably turn out ok.
Planes, looks stupid, started out as a direct-to-DVD movie that's sneaking in a theatrical release, no interest in seeing it.
Turbo, looks like The Onion made a trailer for a kid's movie, not an actual kid's movie.
Free Birds... Wait, crap, I take it back, this is the one that looks like a parody of a kid's movie.

Edit: Oh, and Cloudy With A Chance of Meatballs 2 looks potentially as good as the first one. I'm excited for that.