With Saw VI already in post production and readying for the annual blood drive at halloween Tobin Bell said at the E3 convetion that a seventh and eight films are already being planned and we'll see them as long as the audience wants them made.
Bell says that there is still alot of Jigsaw still to be told and many pieces of the puzzle not yet unearthed. He also said that part 8 is being concieved as the final part but it doesn't mean that a 9th part is not a possibility.
I love the Saw movies, i mean LOVE them. The first one knocked me sideways and 2 and 4 are still amazing to me. The tird one might have been slightly weaker but not by much, it simply fell foul of too much gore and not enough focus on story and intensity. The fifth for me was really poor. It was definitely an exploitation film and didn't further the story where it needed too. Neither was the "twists" or reveals as shocking as they could be. But still, i am still a Saw fan and will be in line on halloween no matter what.