I never wanted kids, either. My wife has always been open to it (FWIW, I'm like 98% no, while she's like 75% no). She has no interest in pregnancy, which basically means adoption or bust. (The ethics of adoption are their own can of worms.) We had an intense conversation about it right before we got married last year. It's one of those memories that will probably stick with me until I die.
Part of me reads a story from Damien or yojoe and thinks, "Hey, that might be nice." Then again, a month ago, we visited our friends who recently had their second kid. Their four-year-old was as wild as we've seen him, and it only got worse when some neighbor kids came over for an impromptu play date. Nothing says "birth control" like trying to maintain a conversation while three four-year-olds shriek, run, and climb all over you.