I would say reinstalling will be required but I bet someone out there will figure out a crack so that an "upgrade" will work. I know they did for the Beta-to-RC route.
My old roommate usually bought multiple console systems, one domestic, one overseas, so he could play the import games. His nerdery was high. He often went to Street Fighter competitions...once in Japan.
My buddy worked at a company here in town (He still works for the company, but now he's located in TX) and they had a keg-arator and Friday was "specialty beer" day.
The "watermark" isn't a watermark so much as just a version display thing. It's a registry key. Previous versions of Windows, you could add it using TweakUI.