When I claimed US citizenship through my parents my financial advisor told me to think long and hard about it because I would be doomed to file a US tax return the rest of my life, even if I don't live here anymore.
The only way you (legally) won't pay US income taxes is if you have enough foreign tax credit to offset what you would pay for US federal tax.

So if you live in a foreign country that you pay income taxes to, you can use that as a tax credit toward your US income tax. Since taxes are generally lower in the US than elsewhere, your burden amounts to the time it takes to do the paperwork to show the US government you don't owe them anything.

That said, I know there are lots of American citizens living out of the US that are blissfully unaware of the rules and have not had any repercussions (yet).