It's funny... minis wargamers vs GW is actually one of the forefronts of that issue. Wargames minis, because they're expensive items, but small, inert, solid objects with no moving parts, made from unremarkable material. Basically a perfect candidate for early 3D printing. And GW because they're so crazy protective of their IP.
Now I do think that 3D printers will have some fairly high restrictions for a while yet. Printing food doesn't solve a hunger problem or really act as anything more than a novelty, because if anything you still need to physically ship raw foodstuffs and I expect printed food to be of even worse quality than fast food. Machine parts with high loads is also probably not a big starter, because if you know about say... car parts, you know that most of them are produced through manufacturing processes designed to affect the material at very fundamental levels. And some materials will never be decent as printables (for instance, no one's going to try and print an aluminum engine block though maybe we'll someday see some kind of high-density super-epoxy) At least not for a very long time. But you may see stuff like side panels, or trim as printables. Or little kit cars with 2HP engines and very short lifespans as a gimmick to show proof of concept.
Even then, home printing will hardly be a be-all end-all. Magic cards have been printed for nearly 20 years, and home printing and scanning has been in place for just about as long, but we still don't see home-printed counterfeits as a big problem for a variety of reasons - even though some cards are worth as much as $1000. That's not to say it doesn't happen, but that it's extremely rare. There's probably a lower percentage of counterfeit Magic cards in circulation then there is counterfeit US currency in circulation.