http://www.namascusa.com/about.htm#history
Here's a little history on the breed.
I do believe that mini aussies are more then just a BYB tactic, as most people seem to believe. There are a lot of good mini aussie breeders out there, there are mini aussie conformation shows, and a LOT of mini aussies used in herding, agility, obedience, etc. There is even a breed standard and code of ethics.
BYBs seem to have pounced on the breed, however. Kind of like how they pounced on toy poodles and such. They're NOT a new breed, but they are a new craze, as people suddenly want small, fluffy dogs. Toy aussies are definitely a product of BYBs. The point of a mini aussie is to be a herder and a working dog, and usually have a MUCH higher drive then the bigger Aussies. If someone is trying to sell a 10 lb toy aussie that resembles a fluffy merle chihuahua, then it's obviously a mutt, or it's been bred extremely far away from the breed standard.
Mini aussies aren't a designer breed, nor are they sickly regular aussies. BYBs have just given them a bad name, just like how people think Chihuahuas are all yappy ankle biters that shake and pee on carpet. And unfortunately, you'll have to do some extreme digging and wading through all the BYBs if you want to find a responsible breeder.