Nikon announced a rather unique product today with the Media Port UP300x and UP300 multimedia playback headset with built-in Wi-Fi capability.
The Nikon Media Port UP300x and UP300 features a display, headphones, mobile A/V player, Wi-Fi capability, high-capacity memory, and power source all integrated into one wearable device.

The display generates a virtual 50-inch large screen from a distance of three meters. The Nikon Media Port has only one display for one eye.
The UP300x is the better equipped version featuring a motion sensor and 8GB internal memory instead of the 4GB the UP300 has.

The Nikon Media Port UP300x and UP300 are also able to be used to browse the web. Not sure how navigation would work though.
Format support of the UP300x and UP300 include WMV9 and MPEG-1, MPEG-2 movies, and MP3, AAC, and WMA9 audio files.

The Nikon Media Port UP will be available only in Japan through the Nikon Imaging Japan Inc. for 69,800 Yen (~$680). See the UPStore site (Japanese). See also the Nikon press-release.