I'm convinced you'll see an eventual collapse of the hobby industry as we currently know it in regard to paying for products already built.
In the future, I see an industry based on downloading product designs that you make yourself with your own equipment. If this follows, then the future will be in design for those downloads, as well as the capability to paint road names on locomotives and cars. That isn't in place yet (as I know of no computer system that can adjust a paint scheme and lettering to whatever scale item is being presented) so probably you'll soon also see an eventual upsurge in technology and suport for pritning your own decals for the 3D stuff you've made yourself. Otherwise, you'd have people making all kinds of cool stuff who have no way to put paint and lettering on it to match what we can buy out of the box now.
I sure wouldn't want to be in the detail parts industry right now with all this coming out, it's a given that 3D printing will become more affordable and reliable as time goes on.
