I went on the premium plan in Dec 05. We stayed at the Poly and had breakfast at our resort (Kona Cafe...the Tonga toast IS to die for) and some of the other monorail hotels most mornings, as we had no car and it is easier.
That said, for breakfast, we enjoyed Kona cafe, Grand Floridian cafe, Boma, 1900 Park Fare...it is a character meal but it is quite good at breakfast.
A few mornings we didn't have breakfast because we were going on tours (we are NOT morning people). If you don't mind counter service meals, I think there are some CS that serve breakfast in the parks (Tusker comes to mind).
Anyway, have a good time!