Ever since being brought aboard the new Star Wars universe, Lawrence Kasdan and Simon Kinberg have been mum about their involvement with the new films. However, the duo recently discussed the new films (albeit in the vaguest possible terms, something we should probably get used to with J.J. Abrams in tow).
Officially, Disney and Lucasfilm have referred to the duo as consultants, but Bob Iger has also confirmed that Kasdan and Kinberg are also working on some spin-off films as well. Neither could confirm too much about those films, though Kasdan is said to have "flashed a Chesire cat smile" when asked if the spin-offs would involve existing characters.
Instead, the two mostly discussed the process of collaborating on these films; Kasdan confirmed that their involvement had been in the works all the way back in the fall after a conversation with George Lucas and Kathleen Kennedy.
Kasdan also had kind words for "Episode VII" director J.J. Abrams, whom he calls a "great director for the first sequel." He also praised screenwriter Michael Arndt and Kinberg and called the collaborative process "fun."
Kinberg mostly discussed the secretive nature of the project and offered the previous "Star Wars" films as evidence that films are best left to be experienced. While he "understands the excitement" and is "happy that people are interested," he would "rather people have something left to discover when they go in." This guy's already well-acquitted to the Abrams system.
In somewhat related news, Frank Oz has also indicated that he would be willing to return to voice Yoda should the diminutive Jedi master appear at some point in the future. However, he also noted that the character isn't likely to return in puppet form, as "the future of Yoda is likely CGI" due to the "physical limitations of a puppet."