Well, this may not be the news you want to hear, but DS who will be 4 in January, is *mostly* nightweaned. He will wake up and want to nurse once in the night about once or twice a week. I would say he started this routine not much after he turned three. IME, it's much different from when he was younger. He'll nurse for minute or two, and I can gently say, "It's time to roll over on to your pillow", and he'll happily let go and go back to sleep. I could probably completely nightwean, but I've started working full time, and I feel on those nights, he's just looking for the little extra connection that nursing provides.
ETA: We have a family bed. Also, I guess some would say that suggesting he roll over is, in fact, weaning, but if for some reason he wants to keep nursing, I keep nursing him.