Having just wrapped up filming his part of Spider-Man 3, J.K. Simmons (J. Jonah Jameson) says there may be more sequels down the road.
Regarding the darker tone of Spidey 3, Simmons told TV Guide: "I think it pulls in a lot of interesting directions. Of course we're a long ways from seeing a final version of it, but my stuff, we had a lot of fun doing. I probably had not as much to do as I did in the second one and maybe a little more than I had in the first one, but from what I saw the new bad-guy stuff is once again going to top its predecessor."
Regarding whether J. Jonah's son John will become a super-strong Spidey foe and then Man-Wolf at some point as he did in the comic: "Not yet. Hopefully there are plenty of cards to play for [Parts] 4, 5, 6.... I'll do a Spider-Man for every two or three years for the next couple decades if they want. That'd be all right!"
And about Spider-Man 4: "Yeah, it got mentioned. In fact, the last couple of days I shot was at the very end of the schedule — we were doing some night-action scenes in New York — and [director] Sam [Raimi] was talking about it. It's not a done deal because everybody's deals, including Sam Raimi's and all the actors', was for three pictures. But he's certainly open to doing more."
You can read the entire interview here.