Will 3-D printers make patents obsolete?

I have a friend who is involved in amateur car racing. He has a 3D printer, which itself was printed from another 3D printer (sans circuit board). If he breaks any hard plastic part on his racing car he replaces it by printing the part out on his 3D printer. Also if any other any enthusiast has come up with a better design for a specific part he can upgrade his existing car parts - like installing a patch to an existing piece of software. For most metal parts he knows a guy with a computer controlled lathe which uses CAD files, again shared from other car owners, to make a one off part, and I imagine the same can be achieved with metal casting as well.

So just as file sharing helped break down the copyright cartels over music, film and text, 3D printing is poised to do the same for the world of patents.
From RTAmerica