I just saw this piece in the weekly print edition of the Christian Science Monitor. It's a great overview of a lot of the offerings out there. In Your idea, "printed" in 3-D, Jesse Emspak writes:
At its heart, this style of "rapid prototyping" relies on a simple concept: building an object one cross section at a time, similar to laying down LEGO bricks to make a larger shape.
The field is still very young, says Scott Harmon, vice president of business development at Z Corporation. Several companies make these three-dimensional printers, the cheapest of which sells for about $10,000.
The products they mention are priced out of reach for most of us, but there is an offering they didn't mention, the MakerBot CupCake CNC, a cheap ($750) rapid prototyper that you can build yourself.
DIY rapid prototyping has come a long way: both Fab@Home and RepRap promise inexpensive rapid prototyping, and are open source hardware designs. They've largely delivered on their promise, in that if you want one, and have the time and/or money, you can get one (there are many tradeoffs in time/cost, depending on where you fall on the spectrum between building one yourself or buying a finished product).
MakerBot is a little different; it's the first of these open source hardware projects that I think is likely to become somewhat mainstream, in that I predict many of us will either soon know someone who has one, or live near a Hackerspace that has one.
Here's why I think that: First of all, it's based on a solid design, the RepStrap, which is a variant of RepRap (RepRap is designed to be able to build itself; RepStrap is the design you build if you don't have access to a RepRap). Second, it's $750 for a kit that goes together easily. Third, it's supported by a community of freely shared 3D designs, Thingiverse. Finally, It looks great on your desk, and has lots of nice touches. For example, blue LEDs light it from within, and the printing platform fluoresces under them.
So if you've got $750, a weekend to build your MakerBot, you can put a 3D printer on your desktop and start downloading and printing out designs from Thingiverse, as well as designs of your own.
MakerBot can't make things as big as the expensive commercial printers can, and the output is not as fine-detailed, but if you can't wait for the future to get here, get one for yourself or your hacker space.