According to cinematical's inside sources,

"in the last few weeks, James Vanderbilt (Zodiac) has turned in a working draft of Spider-Man 4 to the studio. However, according to our source, "his story arc has encompassed two films, making Spider-Man 5 shootable at the same time. The studio saw dollar signs and is in the process of reworking his deal to snatch up the story arc." Don't expect anything immediately, though, since we've been told both sides are still trying to negotiate the deal."

Now don't get too excited, this doesn't mean anything yet. All it means is that there is definitely a script floating around - a script for 2 films, and a script the studios seem to like. It will be interesting to see how this develops and who jumps on board. I agree with Cinematicals comment about it being hard to see Sam Raimi, Tobey and Kirsten jump on board for a 2 film shoot that would easily take up a couple years of their time. Who knows though, maybe we will get lucky and the saga will continue.