Honestly, I reallly hope this doesn't mean a Stormlight Archive movie franchise. It wouldn't work, there is just too much for a 1 book -> 1 film adaptation. Each book could easily be two films at least, so I've always been of the opinion a lot of Sanderson's work would be better suited in a Game of Thrones style TV series, 10 x 1 hour long episodes (maybe even more than 10 episodes per season).
I think Mistborn could work as a movie series, but I honestly think his Reckoners series is more suited for the big screen than any of his other works. But we'll see.