When Hayabusa's sample return capsule was first opened and found to be very clean-looking inside, I doubted that there could be enough material for laboratory analysis. JAXA announced later that they scraped about 1500 dust grains from the inside with a teflon spatula, and these likely came from Itokawa.
I'd been despairing of finding a good source for a writeup of the presentations in the Hayabusa session at last week's Lunar and Planetary Science Conference, but am happy to report that I've finally found an excellent one.
Since I posted an update Monday about JAXA confirming extraterrestrial samples in the Hayabusa sample return capsule, JAXA has posted an English-language version of their press release, which contains a bit more information.
It's official: in a press release today, JAXA announced that some 1,500 dust grains scraped from the interior of Hayabusa's clean-looking sample return capsule are not of terrestrial origin so must be from Itokawa.