Obviously the ports are backwardly compatible, but you were replying to me after I was talking exclusively about the internal USB headers...I meant that from an outside of case perspective. You can plug a USB 2.0 flash drive or any other device into a USB 3.0 port and it will work.
As long as we agree that there aren't enough headers for everyone's needs.Yes, on the motherboard there may be some issues but nothing that an adapter won't fix.