Well, as background there's been a marked increase in self reflection and commentary on some of the show's own tropes the last few seasons (see the Mysterion trilogy of episodes, for example), and some behind-the-scenes issues with Comedy Central and censorship for episodes 200 and 201. Tonight's episode was about Matt Stone and Trey Parker feeling isolated from the energy of the show- the pretext is it's set after Stan's 10th birthday party, where he realizes he's getting old/cynical and not liking the things the rest of his friends do. The South Park "twist" (admittedly a little cliche) is that stuff you don't get (like The Police/Bob Dylan to kids, or dubstep to adults) literally sounds like crap. Again, Randy is the token adult who goes crazy trying to prove that he's young, but at the end of it Sharon and Randy have an ostensible conversation actually directed to the audience from Matt/Trey about how they're moving apart, just aren't into what they loved before, and (Randy/Marsh) decide to get a divorce. Then a montage set to Fleetwood Mac's "Landslide" covers how the boys are splitting apart: Kyle and Cartman are hanging out and actually enjoying each other's company, Stan's alone and cynical, and the episode ends with Sharon moving out and Stan just staring at the ceiling in his empty bedroom.
I have no idea if the show's going to be back this fall.