First of all congratulations for sticking with it. So many well intentioned moms for numerous reasons don't make it to the 6 month and one year mark. Secondly, if you are ready for nursing to be over, then it is time. I just hate that you feel ashamed about it just because of your son's age.
I wish people were more open minded about these things...so neither you nor your husband would feel ashamed. My oldest child also nursed till about 2, but the difference was he also had a little brother who was also nursing. I understand the stigma that you feel and then some.
I became pregnant with our second child when Jacob was one year. He was still breastfeeding and I was not ready to end that. I looked it up online and found that many people chose to continue to nurse throughout pregnancy and even after the new baby was born. I talked with my doctor about it and she agreed that if I ate healthy and continued to do well throughout the pregnancy that she was fine with it. My milk supply did diminish b/c of the pregnancy, but never to the point that Jacob self weaned. Once the new baby came, I was careful to make sure Christopher got all the nursing time he needed. At times, I would have Jacob and the baby nursing. The result for us was that there was absolutely no jealousy b/w them and Jacob is very attentive of his little brother.
We Americans seem to be the most uptight group when it comes to breastfeeding issues. It is perfectly acceptable in other areas to continue to breastfeed until a child is 3.
What it all boils down to though is how do you feel about it? If you want your breasts back (and I totally understand that...I am nursing my third child, Allyson 10 months) then start weaning him gradually. When I did start weaning Jacob, my husband would get up with him in the middle of the night and it never bothered Jacob that he didn't get to nurse. My husband would just pick him up, tell him that he was going to sing him one song then put him back in bed to go back to sleep. It really didn't take that long and my husband enjoyed getting some of the cuddle time that I had hogged all that time :)
Suggestions for eliminating the bedtime nursing...
offer him a healthy bedtime snack like cut up apple/ oatmeal/ even strawberry milk in a special big boy cup while you cuddle up with him and read a story together
he will probably want both at first, but be firm that he gets to choose one or the other. He may go back and forth, but I imagine that he will eventually stop asking to nurse especially if he gets plenty of cuddle time with you. If you want it to be over with sooner, I suggest that you set a date and give him a visual reminder (sticker count down) about the big day that he becomes a big boy and no longer needs to nurse. It may be hard on him those first several nights, especially if he was accustomed to nursing to sleep, but kids are resilient.