The biggest problem with its use in guitars has already been mentioned. Guitar players. Still, interesting stuff, and I suppose it might actually be a good reinforcing rod in a neck layup. Especially if you can figure out how to sell it to guitar players....
See there's no more rosewood left but we swept up the sawdust from the floor at LMII and are now selling these reinforcing rods made of sawdust made from the dawn of rock n roll.... Rose at Seymour Duncan and her niece breathed the same air as when these were made. Guitar players, as much as they hate change - are also suckers for magic beans and juju dolls. So I imagine you'll see it - you just need some marketing genius to figure out the correct sell job.
But seriously you probably will see this in structural components in industry in the future.