I was under the impression they only did lunch & dinner, but we are going to DLR this weekend and my mother in law booked us for 10 AM at Ariel's grotto.
Yes, they offer breakfast seasonally. I thought it was pretty good. First course is a three tiered tray of breakfast breads, cheeses/salami/meats, and fruit on top. Second course is scrambled eggs, bacon or sausage and potatoes.
We did breakfast there in December of 07. We really enjoyed it!! The kids aren't into eggs, potatoes and bacon, sausage and ham so much but they loved the breads and cheeses.