Update: Citing unnamed sources, Ars Technica is reporting that the 802.11n adapter will retail for $100, which will drop the currently available 802.11g unit to $80. No official word from Microsoft yet, though.
Original: Last week we reported that Microsoft was working on an 802.11n adapter for its Xbox 360 console. Microsoft has now confirmed the adapter's existence in a response to Joystiq. The new adapter will effectively double the raw data rate from the currently utilized 802.11b/g, and has already made it to the FCC's hands.
The revamped Wi-Fi dongle will better facilitate the streaming of HD content, and will allow users to "seamlessly connect with their home network with the highest wireless 'N' technology." Redmond offered few details, but it is worth noting that the company referred to the adapter as "another choice to consumers."
Interpret that as you may, but it would seem evident that the new adapter will be marketed alongside the current Wi-Fi adapter and not replace it -- at first anyway. There was no mention of a price or availability, but Microsoft said it would provide more details "soon" and to "stay tuned."