Mindel revealed the news at an industry event in LA, and while I usually don't pay attention to the technical stuff, this is a pretty big deal for the Star Wars franchise. Mindel has worked with Abrams on the last two Star Trek films and Mission: Impossible III, all shot on film. George Lucas famously dumped film in favor of going totally digital for Attack of the Clones and Revenge of the Sith, and the change was instantly noticeable, much to the chagrin of fans. So at the very least, what Abrams is doing now will harken back to the original trilogy, while separating his trilogy from the one that came before it.
I think this is a great move, and with Mindel coming aboard we can safely assume that other new additions will be revealed soon. Star Trek: Episode VII (can we get a real title please?) will arrive in 2015.