I think the biggest mistake made with the Segway was its styling - Kamen is a brilliant man who surrounds himself with very intelligent and very loyal people, but their rationality is a detriment when it comes to marketing; they may see the value in pleasing or emotional design, but they don't strike me as understanding it. The Segway looked like a piece of medical equipment - a very sleek piece of medical equipment, but the smell of the hospital was all over it, nonetheless. Segway needed to have a stylist work on the PT before it ever got into the hands of the media, to make it look cool, not only in its style but in its operation. Toyota has a similar machine coming that is more like a skateboard, and on which people don't look like dorks. Sometimes, great ideas aren't enough to change the world - you've got to have sizzle to go along with the steak.
I think the GM/Segway PUMA is another such blunder; it's the answer to the question that nobody asked. It does nothing for GM, because it's clear that their involvement is little more than the battery technology and the brand name - the vehicle is clearly a brainchild of Segway, and they're not the ones trying to convince the taxpayers that they have what it takes to be a viable company. And unveiling it so publicly when it's still in its underwear, so to speak, is going to make it that much tougher to sell if and when they wrap it in a body. GM's got some good designers - they should've used them to at least temporarily make it look as futuristic as the technology inside it. All GM did with this, I think, is pull out a gun and shoot themselves in the foot with it.