There are a few issues that I think have been overlooked by this discussion.
One is that wearing a light does not always help motorists avoid you. Seeing one light doesn't always tell you how far away an object is, how fast it's moving, or what it is. If you live in a city and a bike with a steady white light is coming at you at night, it's really hard to estimate where it is and when it will get to you, and sometimes lights blend together (background lights from houses and so on). When you see a car coming at you at night, you know exactly how far away it is and how fast it's moving because you know how bright headlights usually are and you know how far apart they usually are on the car.
This is one reason why I actually like the idea of clothing that lights up your form/figure as a person running. Motorists know what people look like, so if they see the figure of a person lit up and moving around at night they'll be better able to determine where the person is and what it is and how fast it's moving.
I don't know about the execution:
-How much will improving leg visibility help? Shirt visibility might be better as others noted...
-Will I want to spend the money for it?
-Will the shorts actually fit me well? I own four pairs of shorts and only one of them fits me really well, two of them fit me well enough that I don't mind running in them, one of those two is so short that I sometimes get comments, and the fourth somehow causes a lot of chafing and I don't wear it unless I have nothing else clean.
-Will they look tacky/nerdy or fun/nerdy, or actually kind of good?
-How annoying is it to recharge the battery?
I think a lot of people have been loudly skeptical of the product because of the corporate undertones, but I think that if I had lights sewn into clothes that I already liked and wore regularly and the battery were already charged, I would sometimes use the lights when running at night.
I've put lights around my hat before (via light-up shoelaces wrapped around it, with the tiny battery packs just pushed under the hat band) and that was fun. I don't do it too often anymore because of the hassle and because I'm not convinced the function is worth it (wearing silly things with friends is fun; by yourself it isn't so much).
I don't think I'd ever use the emergency light function, I just can't imagine it being effective and being able to do it and remembering to do it in the case of an accident...