[antiRepublicrat]

Can you power an external device over Light Peak?

That's the goal. USB doesn't deliver enough power anyway. Firewire delivers a lot more.

[TXnMA]

My research group and I (at a major manufacturer of process control systems and instruments) did a considerable amount of work -- specifically on powering remote instruments via optical power alone. (To deal with safety consideration in explosive atmospheres...)

While I was able to build microsensors that we successfully powered and sensed optically, we never did deliver any seriously usable power optically to do much of anything else.

Unless Light Peak includes some sizeable copper conductors in its cable, all it will be able to do is to transmit signal-level info...