Creator Ryan Murphy said that 'Glee' will come to an end after the sixth season.  The show is currently in its fifth season.

Murphy said that he always envisioned the end of the series to be all about Rachel and Finn, Lea Michele and Cory Monteith.  But with Monteith's tragic death earlier this year, the finale will need to be re-written.

According to Variety, Murphy said,

 ”I knew what the last shot was, he was in it. I knew what the last line was, she said it to him. So when a tragedy like that happens you sort of have to pause and figure out what you want to do, so we’re figuring that out now.”