I have a feeling we'd be talking about Spider-Man 4 if Raimi and MacGuire hadn't walked away from it. Reboot was about the only way more Spider-Man was going to happen.
What happened was, Raimi was originally gonna do it (I, for one, was eager to see him make up for
Spider-Man 3), but was committed to make another film first. That would have put it being released too late to prevent reversion of the rights, so Sony said, "F.U., hippie," and started looking for talent to make a re-boot. I've got to give Sony some credit; at least they didn't go for a no-name hack to do some rush-job, and count on the name of the character to pull in an audience (*cough*GreenLantern*cough*)