As I understand it, Weyless is supergo.com's home brand. They're made in Taiwan, produced in bulk thanks to supergo's unholy buying power and fitted out with components at a stupid cheap price also derived from said unholy buying power. No idea on the quality of the frames, but being made in Taiwan you can safely assume that they're high quality.
Cheaper bikes of a high quality is a great idea IMO, the low participation rates in MTB are, in part, driven by the fact that it's an expensive sport to get into, cheaper bikes = higher participation = media exposure = money = more interest in the sport = higher demand for bikes = cheaper bikes *repeat*