This past week, the official Shonen Jump website has been teasing at a new project by showcasing the letter "D" and now a picture of Shenlong in the background. They have confirmed that a new Dragonball movie is in the works.
特報!! 『ドラゴンボール』映画化決定!!
Special Announcement! “Dragon Ball” set to be made into a movie
More details are to be revealed this Saturday July 14th.
Via: http://shonenjump.com/j/countdown/
There are also rumors that Akira Toriyama will have involvement in the movie's script.