He's making it pretty clear that this is as revolutionary for videographers as the 5DII was for videographers. That would rule out lenses. And he's calling it a device, and implying that it's something to be used on the shoot alongside the camera. And that it'll cost more than $3k.
A stabilization rig is a very reasonable guess.
I doubt it'll have anything to do with audio; you can already get superlative audio for as much as you currently have to spend on non-L primes. I'm thinking of the H4n, that sort of thing.
I also doubt it'll have anything to do with metering or color balancing or anything like that. You just don't need to spend big bucks to get top-quality results.
Similarly, I kinda doubt it'll be lighting equipment. $3k will get you a most luxurious Paul C. Buff studio with multiple Einsteins. I can't imagine the video hot light equivalents being radically more expensive.
So I think I'll go with the consensus of a stabilization rig (or something along those lines). Maybe even with a gyro? Like a whole-camera IS setup, using similar technology as the Segway? Now that could be interesting, even for stills photographers....