I definitely think Bungie is the current front runner when it comes to next-gen dynamic storytelling. I also have a feeling other developers are salivating at the mouth, waiting to get their hands on Destiny. So they can glean some inspiration for their own projects.
Sink or swim, everyone's eyes are on Bungie. Looking for clues as to what's next.
I personally wouldn't say solo frontrunner but sure they can be up there. Innovative storytelling has become a more and more prominent goal of developers since the hardware and gameplay can only be improved so much.
As far as interactive multi-player story experiences they are right up there with Zenimax and ESO and Bioware's single player story telling has always been (in my opinion) well ahead of most of the competition.