Turns out the SpaceShipOne test wasn't all peaches and cream, with problems in stability, attitude control, and composite faring failure making themselves evident. The system is grounded for now until they can sort it all out, but this is a delay, not a retreat. Considering how far ahead they were of all the other teams, I just think it makes it more interesting.
Yes, NASA launches have historically gone perfectly or they haven't gone at all. But that's where most if not all of the 20 times more you pay for NASA launches is going.
Update This informative slashdot comment goes into greater detail about what went wrong with the control system.