[ajross]

You're getting some confusing answer. The simple answer is NO: the USB3 "superspeed" signal is carried on different pins. USB low/full/high speeds carry data in both directions on a single pair of differential wires. SuperSpeed has a separate pair for each direction, and it doesn't share anything with the existing D+/D- lines.

Basically, a "USB 3" connector has two completely distinct signaling environments. It's basically two cables in a single bundle. This is in fact literally true for hubs: a "USB 3 hub" is actually implemented as two distinct electronic devices: one working on the old lines and one on the new.

That said, there is an extension on the Micro B port that allows the extra SuperSpeed pins to be connected in such a way that the port remains compatible with old connectors. I've never seen one in the wild.

[Guvante]

The USB 3 HDD's I have seen have it. [For example](http://www.amazon.com/dp/B005EIGUD4/)