MMW was definitely funnier than the trailers suggested. While The Muppets served to reintroduce the crew, this was more about bringing back the more anarchic side of them.
It was... okay, but it felt like one of the made-for-TV movies (like the uber-cheesy Letters To Santa) with a bigger location budget. The cameos were fun, but none were as amazing as seeing, say, Steve Martin as a waiter or Richard Pryor as a balloon salesman.
The best part, however, is seeing Tina Fey sing and dance with her idol. As one blogger pointed out a few years ago, 30 Rock was a pomo remake of The Muppet Show, and seeing her with Kermit is like seeing Kermit alongside Jim Henson's idols like Edgar Bergen.
I have a modest proposal for the Muppets: keep making the movies more "special" by doing big productions a la Treasure Island or Christmas Carol, but bring back the show for TV. A weekly Muppet Show would be my idea of perfection.
My favorite moment involves Gonzo: a big star cameo asks him whether he's sure about doing a particular outrageous stunt; Gonzo smiles, says "nope," and does it anyway.