Well, the BBC now has a story, "Hayabusa capsule particles may be from asteroid." Apparently JAXA (the Japanese Space Agency) has opened the sample container returned to Earth by Hayabusa, and has released "images of tiny dust particles inside the container."
You will note that I titled this story carefully — Hayabusa has now returned particles from the asteroid. Whether they are asteroid particles or pieces of dust brought all the way from Earth remains to be seen, but they were certainly returned from the asteroid — a remarkable technical feat. This announcement, I think, gives considerable hope that these particles are from the near-Earth asteroid, Itokawa, as the Japanese have been very careful in trying to avoid contamination. Even a tiny speck of dust would be very revealing about the asteroid's constitution and possibly its history as well. Kudos to JAXA for a job well done.