What's really cool is how the Japanese plan to collect samples of the asteroid. They're going to shoot the rock!
When Hayabusa moves in for the rendezvous, expected to be over in a matter of seconds, it will pull up close enough to fire a small bullet into the asteroid and collect the ejected fragments in a funnel-like device. It won't be coming back with much — the amount of material planners hope to capture wouldn't even fill a teaspoon. [emphasis added]
That's a small amount of asteroid dirt. But I'm sure it will keep scientists busy for a long time.
More information here at the Web site for the Japan Aerospace Exploration Agency.