Oh, so beautiful. Allow me a moment to to wipe the drool from my keyboard. I would fab so many PCBs I would have to hook that up to a 20gal shop vac. Not to mention the sound proofing required to keep them both quiet. Don't want to get evicted since it would be running 24 hours a day.

I would build cool custom made project enclosure, giving it a cool professional look. And not to forget making robot such as the bioloid and buttler bot :))))))

Cheamical free PCBs!

i would make signs,sprockets, and gears. gears are hard to make otherwise.

what woldnt i make ? if i had to replace something iwould....CNC IT

Looks pretty cool!

I would make the parts needed for a spazzi robot...I have wanted to finish it for a long time but I don't have the 3d parts!

Hmm...

Attempt to print a desktop milling machine within a desktop milling machine within a desktop milling machine within a desktop milling machine within a desktop milling machine upon my desk.

I'd probably take it for walks too.

Talking from my own CNC milling endeavour, milling basic parts are easy, but for complicated/intricate parts, coming from zero machining background, it will take a very long time and lots of ruined parts before you finally figure everything out and get things right..

CNC milling is not for the faint hearted, lots of things to learn. But going through all that I well worth the trouble..

I would make plastic injection molds.

Oh I'd be going for building / making all the parts of the bots I want to build so I didn't have to buy them, especially the gears if the machine is capable of that.

I would make custom project enclosures, parts for a 3D printer, custom printed circuit boards, use it for engraving items, and all sorts of objects i come across every day and think how it would be nice to have a CNC milling machine so i can make that or replace that. The number of instructables i create would jump up dramatically with one of those things or even a 3D printer. My in home productivity would go through the roof.

Oh I have quite a few PCP boards I would love to cut....but also, I personally would make a large selection of gears, as I seem to always be short of the right kind or sizes. :-)

What wouldnt i make!?

I couldn't even begin to describe to you the amount of things I would make with one...

Well, small intricate models, if it has the capabililties, but for my projects I like to make mockups to show people how it'd work (also, secretly, to test if my idea holds water).
I make puppets, and I'm always trying new joint designs. I find my hand tool skills are not the best, but I like to think I can design pretty well.
Also, there's an artist that does some great stuff for mapping - builds 3 models of landscapes in layers. I'd love to do something like that (reprographics.com, I think). For one, as an economic development officer, the communities I work with could benefit from being able to see clearly what's happening with a given project.
For another, I'm a map-building geek, and it's coooooolllll....

I would first have to stop crying with joy. :) Then I would test it out on every material I can get my hands on. Then I would begin experiment with the limits of the machine, keeping an e-journal of all of my results, with images and notations about pros and cons. (odor, cost of materials, speed requirements and so forth)

I want to create proofs on concepts, functional finished products, artwork, jigs and templates.

And then my focus would probably turn to geeky jewelry.

I second technoplastique's lost wax casting idea. That would make it a lot easier to prototype in wax, as well as replicate the pieces that turn out well. I've only ever done small jewelry, but would love to try something larger such as bofthem's awesome bioshock belt buckle.

Make another milling machine.

I´ll use it to create pieces for customising my bike, with that machine it can be from making designs en the rim or to a little windshield like the moods in their scooters, anything is possible.

Molds for resin casting - waxes are perfect for that. I would also want to try making wax pieces for metal casting. Lost wax would be more fun with that kind of repeatability.

I don't know how much control the z axis has, but I would love to try making bas-relief sculpture panels carved from wood. If shallow 3D didn't work it could still be awesome for carving wood for wood block printing. The precision would make perfect multi-color prints. Any time I see new technology I think about how it could be used to make art.

PCBs made in shapes that are part of the design (like the xmas tree shape with LEDs concept) would be a good use because I could prototype, test, prototype, test; instead of waiting for custom PCBs to be shipped. I haven't worked with this as an element of my designs because it's hard for me to stay focused when I have to wait so long between iterations.

That final image in the video looks like part of a ball-bearing-in-a-channel maze toy. I want to make one of those, now, too.

Or could a 3d object be made by milling a block and periodically flipping it 90º several times?  Stylised chess pieces are an obvious choice.

Signs, name-plates and badges spring immediately to mind, but I wonder what could be built of layers? Maybe a 3d image could be constructed by engraving lines into squares of a transparent or translucent material and stacking them up?