This episode was funny for a lot of reasons. The whole show played off racism in real life and the media, then put the childrens colourless views in as a twist, removing the rasist theme and turning it into one of just violence. It's another example of how this show pushes boundaries, yet remains clever with their material while doing so.
This episode showed us a softer side of Cartman, when he ends up falling for her after she kisses him. The ending is a rather sad one for South Park, just leaving Cartman (as cruel as he is) alone and depressed, walking away...then the scene cuts to credits. I don't know, this struck me as kind of strange; I'm sure it was some sort of intention joke/stab in Cartmans direction.
Over all it was a great episode like much of this season, and is a perfect example of this shows style.