It looks like there's a legitimate working hack for Vista that kills their bogus activation scheme. Microsoft is saying that they're not going to do anything about it yet because they don't know if it will become a wide exploit. But I think this commentor (from the source article) has it more correct:

They didn't think it through as a "hacker" (pirate more like it) would, and now they have a problem. Millions of legitimate users are out there with legitimate hardware sold with Vista. MS can't simply pull the carpet out from under these users. They will need to devise a way that all users can continue using their systems without having to do something drastic like reinstall or update the BIOS because many users simply don't know how to. Even locating the product key on the sticker would be difficult for some.

MS can't simply pull the OEM keys and try again.

But on MS's side, the number of users using this method is very low. And MS have said they'd prefer we pirate Windows than use MacOS or Linux.