I got my replacement SSD at the weekend, and I wanted to install Windows so that it would take advantage of the native UEFI firmware of my Sandy Bridge motherboard. Booting the installer from the DVD will apparently boot you straight in EFI mode as you'd expect (I don't have Windows on disc so I wouldn't know). However, if you create a USB boot drive for the Windows 7 installer, the system will only boot in BIOS mode, and the installer will not let you install in EFI mode to GPT disks.