I'm really not sure. After getting into an argument with a friend (his fiance's American and a PR now) about whether or not Americans can even have dual citizenship, the topic still has me in an "eh" mindset. (He swore uphill and down that it wasn't possible, despite my referencing US government websites stating the contrary. This after also saying they never had to provide any proof relationship aside from statutory declarations--common law. I'm assuming his fiance was the one who did the paperwork...)
I think the bottomline for me--a US citizen who hasn't actually lived in the States since I was a kid--would be trying to figure out how much sense it really would make for me in the end. We don't really have any plans to travel extensively; it's likely that the only traveling we'd be doing would be to the States to visit the odd friend or, perhaps, my currently estranged family down there.
The main thing that has me hesitant is this: http://travel.state.gov/travel/cis_pa_tw/cis/cis_1753.html and http://travel.state.gov/law/citizenship/citizenship_778.html. Evidently, if a US citizen voluntarily applies for citizenship in another country, there's a chance the US can revoke their citizenship. This is ONLY in cases where the US believes the person has shown intent of renouncing their US citizenship. However, they mention that mere conduct can make them come to this conclusion, and with my not having been to the States in several years... it does make me wonder if applying for Canadian citizenship might demonstrate to them that I somehow don't care all that much about my US citizenship (definitely not true). I doubt that it would matter but, without knowing more, I'm not sure I'd want to risk it just to have another citizenship under my belt. Their points about owing allegiance to both countries of citizenship are also valid.
