Does Nintendo Wii support Dolby Digital audio ?

No. Wii does not feature an optical output and therefore no support for the Dolby Digital surround sound standard. Like GameCube, Wii's audio output consists of left/right analog channels that simulate surround sound using the Dolby Pro Logic II matrix. Most, if not all Wii games will run in Dolby Pro Logic II. That noted, due to the increased storage capacity of Wii discs and in turn the ability for developers to include less compressed audio files, games on Nintendo's new generation system should sound crisper than those on GameCube.