Well, it seems that there now won't be a Spider-Man 4, and that the studio is rebooting the franchise. Here's a bit of what we know, from Deadline Hollywood (the whole article, and its updates, can be found here):
Mike Fleming and Nikki Finke have just confirmed that Sony Pictures decided today to reboot the Spider-Man franchise after franchise director Sam Raimi pulled out of Spider-Man 4 because he felt he couldn't make its summer release date and keep the film's creative integrity. This means that Raimi and the cast including star Tobey Maguire are out. There will be no Spider-Man 4. Instead, Mike Fleming is told, the studio will focus on a Summer 2012 reboot from a script by Jamie Vanderbilt with a new director and a new cast.
-Thoughts on the direction Spidey is headed?