They should work at USB 2.0. Worst case is that they'll work at USB 1.1, but they will work. I only use my front connectors for things like joysticks/game pads, so I wouldn't notice a difference anyways.
Confused: As for a wire's capability to handle the bandwidth difference, good luck trying to run an ATA133 drive at 133 (or even 100) speed with an older ATA66 cable. Both are 80 conductor cables, but an old ATA66 cable won't do ATA 100/133 transfer speeds. You will also have equal luck trying to network at 100Mbps with cable only spec'd at 10Mbps. Cables can and do make a difference.