I've always been interested. I was just joking with Michael that if I didn't have the doggy morals I did have, I would love to have a dog to stud out - four litters or so and I could pay off my student loan. LOL (It's not a very big loan.) However, I don't think I'd have the energy or funds to have a breeding program that involves highly competing (aka, multiple sports) with multiple dogs. So, if I ever wanted to "breed", I'd likely have a brood bitch for another breeding program/service dog organization.
I have also joked about creating a breed of dog like Cynder. Seems like they are in popular demand, but not one breed is exactly suitable. Medium size, wash and wear weatherproof coat, mild mannered, social yet unobtrusive, weekend warrior, quiet, great with kids/other pets, trainable, etc., etc. Basically, a good average pet dog.
But if I don't have the time or energy to compete with multiple dogs, I can't even imagine starting a breeding program!
So, short answer: as a flight of fancy/BYB channeling, yes, I've considered breeding. Realistically, no, will likely never happen.