If wmv-hd can compress the 1080p content on a simple dvd, why is blu-ray for?

Its annoucend on the microsoft web page that you can buy those wmv-hd (vc-1) with fullHD resolution, and play it in any (powerfull) computer with regurar dvd drive on it. If that happens, why are we in need for blu-ray if some of the blu-ray movies also uses the vc-1 codec? Related Blogs Create a [...]