Microsoft has announced that the Xbox 360 Wireless N Networking Adapter revealed in September will hit North American shelves this week with a recommended price of $99.99.

The revision adds support for the 802.11n wireless protocol which Microsoft says will offer up to "two times the range and a speed seven times faster" than the previous adapter when used on an WiFi-n network.

The adapter will also work with older 802.11a, b and g networks, and naturally supports the WPA2 security protocol--a feature added only recently to the original version.

Joystiq reports that the recommended price of the original 802.11b/g-supporting Xbox 360 Wireless Adapter will be cut from $100 down to $80 "while supplies last."

A new Xbox 360 system update is rolling out this morning, bringing support for the WPA2 security protocol to the Xbox 360 Wireless Adapter. Owners will be prompted to download the mandatory update when they next sign into Xbox Live.

Microsoft's Larry 'Major Nelson' Hyrb stresses that the update does not include the upcoming Facebook, Twitter and Last.fm integration nor the Zune Marketplace 1080p "instant-on" streaming video, which are all scheduled to arrive "later next month."

A new version of the Wireless Adapter with support for 802.11n in the works.