They're going by the name "3-D printer" right now, but the overall idea is a home fabrication machine capable of producing complex 3-D goods (including moving parts, electronics, etc) on demand. Current 3-D printing is an extremely crude version of the eventual device.

So if you wanted a new microwave, go online and download the design. Then go to the Christmas Tree machine and have it print one up for you. Just like presents under a Christmas Tree, you ask for something, say the magic words, then it appears with a little bow on it. (It occurs to me they should have been named Santa Claus machines, but I don't make this stuff up, I simply repeat it)

Of course, we're starting off with extremely simple implementations. I think the current technology does stuff like figurines. Adding moving parts is probably a next logical step, then printable simple electronics.

There's a long way to go, but once realized, Christmas Tree machines will change everything.