You kind of pay the maximum of the US and domestic tax rates, after some possible deduction, though not exactly the case given how it gets calculated. But yes, all income worldwide is taxed for US citizens. If you're curious, see:

http://www.irs.gov/publications/p54/index.html

You pay after the first $92.5k. you pay the difference between what you would be taxed in the US minus what you are taxed in your current country. This only becomes a problem if you are living in a country with no or low taxes; ie, HK, Dubai, Saudi Arabia, the Caymans, etc. If you live in Western Europe you are being taxed higher than in the US.

Switzerland is a difficult subject because they don't identify you when they report your taxes so the IRS has to trust the Swiss gov't is telling the truth. I believe they have reached an agreement that favors the US and have a lot of Swiss account holders pissed off.