I wear my 4 and a half y.o. in the Kinderpack for preschoolers (3 to 5 y.o.), it is wonderful.
just like the ergo, but deeper, so it covers up to the knees of the child.
I live in Canada, so with duty taxes and shipping, it is a bit expensive, but I have used it more then my ergo and beco, so well worth it. And it is the only carrier for that age group that I know of.
Toddler/Preschool Kinderpack, or if you like the close feeling of wrapping, I'd recommend a Bloo Kangaroo Kanga. They make a toddler (XT) and preschooler (XTP) size. I have both brands for my year-old son, and highly recommend both! :)