They all draw from the same common source of pop-culture paordies. I don't think there's a single ____ Movie that hasn't parodied Star Wars, the Matrix, or Spider-Man, and this is a bad thing.
If anything is likely to kill modern humor, it's the ____ Movies (Meet the Spartans included). Nowadays all it takes to make your average Joe laugh is to quote "I am your father", make a poop joke, and have a crappy actor do an impression of a celebrity that was briefly in the headlines a month before the movie came out.