It appears that Apple is now supporting USB3 in OSX:
the new "Retina" MacBook pros have dedicated USB3 ports. Question: has
anyone tried using libdc1394 on OSX+USB3, yet, with a camera like the
Point Grey Flea3 USB3?
Some reports indicate that as of today (mid-July 2012), the USB3
implementation is still somewhat buggy. Apple has posted a small tech
note about using USB3: http://support.apple.com/kb/HT5172
Interestingly, Apple states that the USB3 port will work properly on Windows7 via Bootcamp.