One of our fellow backers found a very interesting article on Gamasutra. Although it’s nothing legally binding, it’s exactly the same interpretation most of the backers have and that are strengthened by kickstarter’s blogpost about liability.
The article is a great help when arguing with third parties that might see kickstarter as an investment platform (Triggertrap indeed puts great effort into letting backers think that’s the case). To make it short: It isn’t. Backers don’t get any share in a company/product and don’t have a chance of great gains by taking this risk. Backers pay a price that’s very close to the market price of a “reward”, thus simply preordering it.
An example from the article makes a nice point: When a farmer sells the corn of his fields, although they are not harvested yet, he still is obligated to deliver. He cannot say that he did not know that it would be so hard to get it and thus just pays back what’s left from your money. After he used it to buy new tools, pay his own and workers wages, etc. There is a popular meme, describing this problem.