It's inevitable to happen. History has shown time and time again that anything that becomes over saturated to death shale be finished of with a parody. Blazing Saddles finished off the Western. Airplane finished of the Airport disaster films. Weird Al finished of Michael Jackson's over played singles time and time again.
Nobody is safe from the parody.
Sometimes, however, the parody fails to finish off a genre. Take for example the film, Student Bodies . Here is a movie that made fun of the 80's slasher genre long before the genre even began to die off. This could be because of several things. Perhaps it just came out too soon.