I wondered when they were going to start doing that
How do you know if it's legit? Well, it's sold as supposedly legit, with certs and everything. If it comes out that it's not, you can sue them for fraud and any damages recieved for using an illegal copy of Windows unknowingly. Then you can actually afford MS's over priced crap...
EDIT: Where'd you hear that DD? I'd like the same news source