Personally, I think that fruits are largely interchangable with veggies in terms of their nutritional status. And a good thing, because I eat very little fruit due to my food allergies.

I'm not anti-dessert, actually - I wouldn't see anything wrong with a toddler having a little bit of ice cream or a cookie or animal crackers or something nearly every day. (Ordinary-sized cookies, not the big cafe cookies.) But that's in the context of a healthy overall diet! Solid food is such a small part, nutritionally, of 7- and 8-month-olds' diets, that I can't imagine having part of that be dessert.