I like the idea, in general.
I am a bit puzzled as to why this system relies on batteries, as opposed to using Electro Magnetic Induction, to power the lights. Reelights do a splendid job of tapping into EMI. May be they will come-up with one, when the product is fully developed and it goes into production.
I had the Reelights on my Americano for a long while. Right now, they are off, as I have installed a SON hub dynamo, on the Americano, which powers my front and rear lights on the bike.
What do you think of the Revolights? Minimally, they should at least be attractive to the "younger" cyclists.