The books are still being written, and the show is following the plots written (for the most part, although there have been some changes). I dont see why they would stop before they reach the end unless at some point the show stops turning a profit.
How much longer you think it's going to last? Just because the comic is still going doesn't mean the show will keep going. The longer the show, the more it costs them to run and harder to turn a profit.
