My DS is sixteen months and still nursing his little heart out. My best friend had nursed her daughter until she was about fourteen months old. And we've talked a lot about how similiar the two kids are, her daughter, like my son, are VERY attached to us, not the greatest of sleepers, really physically active, etc. My DD is the same age as her's, and the two girls are not all that similiar, my DD is a lot more independent and confident. My DD gradually nursed less and less, and by the time she was eight months old, she was completely done. My goal with my DS was to make it to a year, but he's still nursing several times a day, and usually a couple of times at night.
Last night, my DS was up all night. Literally nursed all night long. He's cutting some molars, so it was a restless night. We co-sleep, but I usually just doze when he's nursing, as opposed to actually sleeping. I was on the phone with my friend earlier, and she commented that I sounded really tired, and I told her that Sam had been up nursing all night. She told me that I'd just have to wean him, she went away for a week to wean her daughter. Sure it was miserable and awful, but if she hadn't done it, she figures that she'd still be nursing. And I kind of laughed it off - I didn't tell her that there's no way I'm going to go away for a week and just leave the kid screaming for me. As much as I wish that he didn't need to nurse, he still does.
And what I realized was that one of the reasons her DD is so attached and clingy, wanting to be carried and held all the time, might be because she wasn't nursed as long as she needed to be, and that the ending was so abrupt and painful. And I'd much rather have a really clingy toddler than a kidnergartner that wants to be carried instead of walking. If I nurse him as long as he wants to, then he'll outgrow the need for it, right?