It won't take very long for hackers to find a way around the nag screens.
The thing that gets me is that these people will be offered to buy a legit copy at a much lower rate. It seems to me like that is encouraging pirating. If I want to buy Vista, I just have to download an illegal copy, then buy it a lot cheaper. Unless this is a sneaky sting where they will prosecute anyone who tries to accept that offer.