Rudy, that is absolutely false. If you run D:\Drivers\Apple\BootCamp64.msi on your Snow Leopard DVD, Boot Camp 3.0 will install on a PC.
Next, you can update from Boot Camp 3.0 to 3.1 using the official Apple update. Finally, you can then install the Apple Magic Trackpad and 27-inch LED Cinema Display Update. This should enable brightness control on the PC.
As far as connecting the ACD27" to a PC, you can buy new PC graphics cards with DisplayPort or miniDisplayPort connectors, i.e. ATi Radeon 5970, Palit GTX 470, etc. You can also connect older DVI cards with the ACD27" using an active DVI to mDP adapter such as the Atlona AT-DP400.
My LED Cinema Display 27" is still in the mail so I haven't tested it yet with my non-Mac Bootcamp PC, but other users at Macforums.com are saying that yes, the ACD27" is PC compatible.
Short answer: yes.