Microsoft made the Wireless N
adapter for the Xbox 360 official today
and you can pick it up later this year for the overly expensive price of $99.99. The new adapter will feature two antennas and support the a/b/g and n wireless specifications which means you can now receive data at close to 600MB/second under ideal conditions. It's still slower than a nice 1GB hard wired connection but should still help with the streaming of HD content to your Xbox 360 assuming you're willing to dish out the dough for the connector and a Wireless N router (which could cost you less
than the 360 adapter).