First off, I'm not talking about the luxury cuts. There is a visible difference between a Kobe ribeye and one from the local megamart. But it seems like you can't throw a rock these days without hitting somebody selling "Kobe" burgers, "Kobe" beef hot dogs, "Kobe" sausages, etc.. My butcher sells Wagyu "london broil" (top round?) for about double the cost of a choice cut.
Without getting into the nomenclature issues, how are these products different than run-of-the-mill beef? The main distinguishing feature of a Wagyu ribeye--extensive, well-distributed intramuscular fat--just isn't present in a top round steak, and it vanishes when you grind the meat and form it into patties or extrude it into casings. I mean, you can get perfectly "marbled" hamburger just by throwing extra fat into the grinder.
So, is there something else that distinguishes Wagyu from other types of beef, or have the producers just found a way to get a premium price for the parts of the carcass that are left after the distinctive cuts have been sold?