Reportedly, the character of Lewis Dodgson (played by actor Campbell Scott this time) will return, possibly meaning the return of JP's original villains-the company Biosyn, Ingen's rival, who bribed Nedry and pretty much caused the whole incident in the first place.
While The Lost World novel and pretty much every comic book or video game continued to portray Biosyn and Dodgson as the main antagonists, the films pretty much took a different approach-with the human bad guys mainly coming from within Hammond (and later Masarati's) company, Ingen (James Cromwell's plan was also corrupted by his own subordinates).