I did a quick pass through the tree tonight eliminating all the devinfo stuff. This code had been implemented in uhub a while ago, but the client drivers were never updated to remove the bloat. We set the device name to usbd_get_devinfo in uhub, but then in the client drivers, we computed it again, and printed it, so the data would appear twice.
So far the only wrinkle is that kldunload/kldload doesn't set the description, but there are bigger problems there.
I hope to investigate a few of the bigger usb problems before 7.0 branches and get them fixed.