Oh, cool. It took me a while to read the link because it sounded like another one of those pipe-dream ideas that tend to get hyped and linked on Slashdot with no follow up. Having raw materials to work with in space without having to fight the gravity well would be a *huge* step.
EDIT: Yeah, I groaned when I heard the word unobtanium in that Avatar movie. It has been in long usage to criticize sloppy stories in the Sci Fi community.
EDIT again: I'm curious as to what exactly they are going to use for thrust to move these asteroids.