I wonder if this is part of the new push to make these companies more immune to the NSA? In otherwords, they can say 'sorry we don't have the encrypted USB', similar to the new updates to Android, and iOS that give them 'zero knowledge' to disclose to the NSA, even with NSL's.
It's cool, more companies should offer this, and it should work in all browsers. Perhaps also an idea to offer software based tokens that are tied to a single PC.
"The Google Security Key system only works in Chrome right now, but if other browsers and additional sites implement the U2F protocol, the same Security Key will work with them, too." From the link at the original post.