It's all about capturing emerging markets, not holding onto already established ones. Established markets are easy to get into if the technology is already developed, etc. IE the manufacturing base, exporting natural resources, etc.
It's all about the US patent office and whatever the new hot shit that is coming. Biotech, genetics, green tech (not a lot of profit IMO). The US still has massive purchasing power, a huge consumer base, a huge GDP based on intellectual properties that no other country can touch, we still pull the best and brightest from other countries (including China), etc., etc.
The US CANNOT stay on top forever, but we aren't going to go into a free fall. We just need to get over ourselves, get better with out money, make our education system more EFFECTIVE and we should always be able to be competitive as or with the best for the long-term.