Sony is so confident that Spider-Man 3 will be a hit that both the studio and Marvel are in active talks about doing more movies with the current cast and film crew. Talks between Marvel and Fox have not gone so smoothly.
At the time of X3’s release, it was widely reported “well this is the last movie” despite the last scenes that were shown. Then the Box Office results kind of made Fox change their minds, at least all of a sudden they became more open to the idea of doing an X-Men 4.
But Marvel has an alternate plan for the future of these movies. One that Fox is reluctant to take seriously. However, they may have little choice in the matter because ultimately the X-Men are Marvel’s characters and with Marvel making even bigger steps to control and have more say in the production of their movies, the news on the future of the X-Men movies (which will be revealed in good time).