I have searched the archives for a long time but I haven't found a concrete answer to this question. It doesn't matter that much to me but it would be nice to know. I have managed to break several axles and it's nice if they are easily replaceable.
The Miche hubs listed on our site are holdovers, we didn't get them from QBP, and haven't adjusted the price. The reason for this is because we really don't recommend the Miche track hubs, mainly because they come with really cheesy nuts, and they use an oddball thread that you can't get decent track nuts for without paying ridiculous prices. They're also single sided, not flip-flop.
So either they changed the design, or Gene Spicer from Spicer Cycles changed them out for me before he sent them. He's a really good guy, I wouldn't be surprised if he did that. Also, mine is flip-flop (fixed/fixed).
EDIT: others in that same thread report getting their hubs with real track nuts. I wonder what's up with that.