You could always keep hoping that the Supreme Court will declare income tax unconstitutional again! 
If only they would declare it unconstitutional!!
In 2002, I decided I should file my US taxes for 2000 and 2001 since I hadn't bothered before. I knew I surely wouldn't have made very much anyway so that's why I hadn't filed. It turned out I was owed a bit for 2000, so I was pretty chuffed on that front. I've been good about filing for 2002 and 2003 (I do it on a Jan-Dec basis. Much easier for me); however, I haven't bothered this year. I don't see the point really. Why should I file when I don't even live there AND when I know I don't owe anything? I might do it in the next few months. I love the UK system since I don't have to worry about it at all -- unless you are self-employed, etc, but then I'd have an accountant do it!
On a different note: I know you're allowed up to $80000 of Foreign Earned Income, but does anyone know what happens if you earn MORE than that? Not that hubby and I will any time soon! We currently earn -- jointly -- approx $62,377.
As for renouncing US citizenship, I wouldn't do it all. I find it quite a chore to file my US taxes and even though I don't visit often, I always like having the option of moving back there without much hassle. Of course, all my family are there so I have ties, but I personally wouldn't do it. I have a US passport, which allows me easy entry back into the US, as well as a British passport, which allows me easy entry within Europe.