Clean Install with Windows 7 upgrade on sale now?

Solution
From the MS store:

Running Windows Vista? If you have Windows Vista, you can purchase Windows 7 Upgrade versions. You can do a clean install (back up your files, clean install, and reinstall your applications) or an in-place upgrade (Windows 7 installs over Windows Vista).

Running earlier versions? If you have Windows XP or Windows 2000, you can purchase Windows 7 Upgrade versions. But you must back up your files, clean install, and reinstall your applications.

So yes, clean installs with upgrade media will be possible.
From the MS store:

Running Windows Vista? If you have Windows Vista, you can purchase Windows 7 Upgrade versions. You can do a clean install (back up your files, clean install, and reinstall your applications) or an in-place upgrade (Windows 7 installs over Windows Vista).

Running earlier versions? If you have Windows XP or Windows 2000, you can purchase Windows 7 Upgrade versions. But you must back up your files, clean install, and reinstall your applications.

So yes, clean installs with upgrade media will be possible.
 
Solution
I just intalled the Win 7 Release Candidate a few days ago. Had Vista on the pc - first I backed everything up, then tried to install Win 7 as an upgrade - it went through everything, but eventually failed. It also gave me the option to to a clean install, so I tried that and am typing this reply on Win 7 Ultimate RC right now. Beautiful!

So yea, with the info Zoron provided and my experience w/ the RC, it looks like clean install will be an option (and based on my experience with all prior versions of Windows - clean install is much preferred).