It is very interesting to see the group move to a switchable voltage, expecting to support 5V, 12V and 20V. My first reaction was 'oh no.. going to fry some 5V

It is very interesting to see the group move to a switchable voltage, expecting to support 5V, 12V and 20V. My first reaction was 'oh no.. going to fry some 5V electronics with 20V' but if all the negotiation is done right - and not too easy to spoof it should keep people from building cheap adapters to go inline, request the wrong voltage and fry things. The voltages are a nice choice. 5V: backwards compatibility. Everything is 5V. 12V: same as your car - lots of things run on 12V. It is easier to build a step down converter than a step up. so that gives the hackers some options. 20V: It was genius of them to step up to 20V. as others have pointed out, charging a laptop (often 17-20VDC required) is perfect. This is also a good choice for keeping the conductor size small in the cable. We get to 100W (wow). now if you really want to be forward thinking, maybe look at the way electronics have moved from 12V, to 5V, and then to 3.3V. If they want this to be super portable for future use, maybe put in 3.3V - although I can't think of what it would be used for right off.