This is cool because they "printed" the entire DNA double helix end to end, one molecule at a time, and it was viable (i.e. grew and divided into more cells which were also viable). No more messing about using viruses to inject a desired gene into an existing organism. We can make the whole thing from scratch.
Well, TW is right, they had to put the first DNA strand into an existing cell from which the nucleus had been stripped, but that was just to get it all going.
Next stop ... designer cells. Feed 'em sewage, have 'em turn it into bio-diesel or whatever. That kind of thing.
What could possibly go wrong?
