First, you have to be capable of imagining where a rapid prototyping machine has its strong points. Obviously you aren't going to spend 2,000 for the ability to print a chair to sit on. However, if you were someone who designed chairs regularly, 2000 might be a small cost to be able to spit out a computer modeled prototype right there in your home at a fraction of the cost of a prototype house.
I personally use mine for custom attachments to gaming controllers for people who have physical disabilities. The cost to print one (that is actually usable) is nothing compared to the thought of tooling and minimum orders.
There is TONS of hype out there. However, there are also legitimitely great things happening as well.
@Max...re lathes...a friend of mine had a Myford ML7 (3.5" swing, 20" bed) which I spent many happy hours playing on (and did some useful stuff!) For really small stuff (less than 2'' x about 5" or 6") there was a thing called the Emco Unimat. But both are expensive - I saw a Myford for $1250 on Ebay and a Unimat for $500+. I guess there are other things these days, with CNC no doubt. I so need to win the lotto......