There were certainly some great Piggy moments here, especially her little backstory on why she was so upset at the fact that she might not host the show, but thanks to a little ingenuity from Kermit, the show went on yet again. I also liked the B-plot with the rest of the gang holding Pache hostage and answering his phone for him, which ended with a sweet emotional payoff. I hope this doesn't mean we'll never get to see him again, as I feel that his impact on "Up Late" could have been felt stronger.
As for the classic sketches, I especially liked the twist with Vets Hospital in that Rowlf was about to operate on an actual human patient rather than a fellow Muppet. The Swedish Chef/Muppet Labs fusion was pretty good, too.