In an interview with MTV [1], Sam Raimi announced that SPIDER-MAN 4 would go into production in March 2010. Sony and Marvel Studios still hope to have the film in theaters on May 6, 2011. Raimi said that writer Gary Ross is still working on the script and Scott Stokdyk will return as the visual effects supervisor. Stars Tobey Maguire and Kirsten Dunst are set to return.
Links:
[1] http://splashpage.mtv.com/2009/10/09/exclusive-sam-raimi-hopes-to-start-shooting-spider-man-4-in-march-2010/