I won't be due for citizenship until March 2011. I just barely (by about three months) come in under current guidelines and regulations. I wanted to get it because it was such an ordeal getting over here in the first place (really, things went smoothly, it just seemed like an ordeal in my head with all the what-ifs).
If we stay, though, as our original plan was, in 4 years, it puts our oldest child at age 17 moving, right between high school and college age, with no drivers license and no work experience and no instate tuition... Unless we move in 3 years, which would be months after applying for citizenship, and to avoid that overlapping, may put them in the middle of the school year. If it was 100% up to me, I'd stay. As much as I miss my family and friends, it just feels too rushed to get everything done to be gone by this time next year.