Well Ryan, the guys who flyfish for yellowtail, bonito, etc along the kelp beds off San Diego are BIG into kayak flyfishing. As a matter of fact we have a couple members who are LaJolla yak masters. A big yellowtail will definitely give you a sleigh ride.
Up around the San Juans, one of my favorite places in the world, there is a pretty quiet coalition of yak anglers, or should I say angling yakkers. They bring the fishing stuff along as avid yakkers most likely.
Washington state SWFF is absolutely IDEAL for kayak flyfishing - particularly for transportation. I don't think I would fish from the yak personally, but I love the idea of getting around swiftly and silently on Hood Canal, Puget Sound, Grays Harbor, Willapa Bay, etc.
Around New England, the coastline offers endless possibilities for kayakers. There are more ponds than rivers, unlike the beautiful pacific northwest where the opposite is true. In the northeast nobody owns a driftboat, except for Great Lakes tribs. I sold my Clackacraft last year due to lack of places to use it. The guy towed it up to fish Lake Ontario tribs.
I'll bet it catches on. Makes the searun cutt fishery infinitely more interesting along Hood Canal, for instance.