PC users who run Windows and Linux on the same machine will want to do some research before purchasing a Windows 8 computer. That's because systems with a "Designed for Windows 8" logo must ship with UEFI secure booting enabled—a move that prevents booting operating systems that aren’t signed by a trusted Certificate Authority.
This could pose a problem for Linux users, though in practice most can just change UEFI settings to disable secure boot before installing the open-source OS. But users will have to depend on hardware vendors to make this option possible in the first place.
Ah, the long awaited UEFI that will replace BIOS... I'm sure by the time Win8 is out they will have ways to disable secure boot for those who want to dual boot.