The issue with the South Park finale was more the fact that it had Matt and Trey basically talking to their audience under the veil of an argument between Randy and Sharon (lines like "this is getting old", "it's the same shit week after week", etc.). Then they had Stan completely alienating himself from the other boys, Randy and Sharon splitting up, and Kyle and Cartman becoming buddies. And that's how it ended. No predictable reset, just a weird, depressing ending. It really made it seem like they wanted to end the show.
Apparently that's not the case, though, since they just signed a contract with Comedy Central through 2013. Woot.