Question about Windows 8 Pro

Hey guys, what's up?

As we are getting close to Windows 8's launch, I am making my mind of which way I will use to buy my copy. At first, I thought I should download it because it will be cheaper but I was wondering if Microsoft will allow us to download it back again if we want (like Apple is doing with iCloud and the Mac App Store for OSes).

If not, I guess I'll get the boxed version.

Thanks guys!