Danny Postel at New Humanist frets over his kids, with their theistic mom, freethinking their way to possibly religious conclusions. I suppose it is the sort of thing that the more passionately atheist would worry about--which might have been a reason not to reproduce with a theist, from their perspective. He goes on to talk about some "humanism for kids" books that he seems justly ambivalent about, and does ultimately admit his kids can and will ultimately believe what they decide to believe.
But his article made me wonder. His kids are 6 and 10; how many educated adults have the same beliefs and attitudes about religion as they did at that age? My knee-jerk thought based on introspection and looking at my peer group says, not many. Not sure if there's any research on this specific topic that's thought to be bulletproof and authoritative, but I'm skeptical how much hand-wringing over your kids intellectual attitudes at age 6 and 10 is warranted.