Windows 8 Developer Preview

Hi– yesterday i downloaded windows 8 developer preview and i really like how it works as far as testing out windows 8, but my question is say if i stick with windows 8 on my home computer and when it comes time for Windows 8 to be released on computers to the public can i buy a windows 8 upgrade key or product key and change the product key on my computer so i can keep using it down the road with out having to reinstall windows.

Let me know what you think?