From my understanding the Blue Delaware is a completely different breed and doesn't have anything to do with our Delaware breed. It's more of a game cock. Here's a link to wikipedia with some information.
http://en.wikipedia.org/wiki/Delaware_Blue_Hen
As far as production goes I'd like to breed towards a big framed cock for meat and a hen that is a good layer, especially in the winter. I wouldn't expect them to lay eggs like a commercial leghorn but I would hope for 200+ eggs a year. That being said, I've never tracked my current flock and perhaps I should but boy would that be quite an undertaking! The SOP only says "
a dual purpose fowl with well developed egg and meat characteristics." The only time the SOP defines numbers is for weights, tail angle and number of points on a comb. It would be nice to know the original goal of this breed.