My initial goal was 2 years, and then I toyed with the idea of child-led weaning after that. I had big time nurseaholic kids who at 2 were still nursing upwards of 10 times a day. I tried to get them to cut back a little (most of my friends who were nursing their toddlers of the same age, were only nursing 2 or 3 times a day at that point), but it never worked. We would either nurse all day, or fight about nursing all day, and I eventually weaned them not very gradually at 28 months. One of them was totally fine with being weaned, and the other wasn't, so I started nursing him again and continued nursing him until 36 months when I got pregnant and it became too painful (but he was only nursing once a day or so by then). It was really nice to just nurse one toddler! The ds who weaned later is planning to start nursing again when our baby comes. . . I'm guessing that he's probably forgotten how, but I'm willing to let him try! With this baby, I hope to do CLW, or at least nurse until age 3.
Nursing twin toddlers is definitely different than nursing one toddler. Not just because there are twice as many nursing sessions, but because they really get jealous of each other nursing, and I think, at least with my kids, they nursed more than they would have had they been singletons because they both HAD to nurse everytime that one of them got hurt, etc. I definitely have some regrets about both weaning experiences, but I know that at the time I felt like it was necessary.