According to this article from Deadline:
Colin Trevorrow, who made his feature directorial debut on the no-budget Sundance pic Safety Not Guaranteed, is about to make a Tyrannosaurus rex-sized leap in scale for his next film. He has been set by Universal Pictures to helm Jurassic Park 4, the third sequel to the dinosaur franchise hatched from Michael Crichton’s novel.
Sounds good to me. Safety Not Guaranteed was an overall good movie, especially for its budget, though it’s dirty humor side-story was pointless. But I’m sure we’ll not see that brand of humor in Jurassic Park 4 with screenwriters Rick Jaffa and Amanda Silver. This installment, planned for a 3D release in 2014, is sure to be better than Jurassic Park 3. I’m looking forward to it. In the meantime, the 3D re-release of the original Jurassic Park is coming next month.