Though nothing has been made official yet, Nikki Finke over at Deadline Hollywood says the deal is done to bring both Tobey Maguire and Sam Raimi back for Spider-Man 4 and 5. Not only that, but Finke also claims the exclusive on a story we broke right here at Cinematical months ago (thanks for the credit Nikki) -- that Sony plans to shoot both films back to back, not just because it's cheaper, but also because we were informed that James Vanderbilt's (Zodiac) script included a story arc that encompassed two films, not one.
As far as Kirsten Dunst goes, she currently does not have a deal, but Finke claims her character will return and Sony is not interested in recasting her. Villains? While there's been no announcement yet, a source claims that "once you find out who the villain is, you'll know who's playing him." Naturally, that leads everyone to believe that Dylan Baker will reprise his role and ultimately become The Lizard. Should they continue along the same path Spider-Man 3 went down, one imagines another villain (or two) will show up, perhaps as a way to tease us into the fifth film. I'm sure more will arrive online soon, so until then ... are you happy about Maguire and Raimi returning to the franchise?
Spider-Man 4 is currently scheduled to arrive in May, 2011.
UPDATE: The Hollywood Reporter confirms the Spidey story today.