Well Hobie just needs to work out the reverse thing (big) and they've already got the 17 footer. Probably a deep sea kayak 24' footer on the horizon..
I noticed in that one clip in the video they show the red kayak under power, and it's really plowing through the water, and it looks like a powerful motor. Better prop design you might get a little bit more efficient power, but with a kayak your pretty limited by the hull design.
I see E powered kayak racing in the future!