Yeah... No. The key is the "Xlink-Kai" which is an UNOFFICIAL system for playing multiplayer games. It might work for when you're playing via Xlink-Kai, but it won't likely work at any other point.
What you might want to look into is call a wireless ethernet bridge. It's a little device that takes a wireless signal and converts it to ethernet. Of course 11n's top theoretical speed is higher than 100Mbps ethernet, so you'd lose some on paper speed by doing this. In reality, you're never going to even come close to those speeds, so don't worry about it.
Of course the Wii already has Wifi capabilities built in, and honestly the move from 11g to 11n isn't going to really have any net gain as far as gaming goes. Wireless SUCKS for gaming, end of story. It's not a matter of bandwidth, since even 11b has more bandwidth than the average broadband connection, it's a matter of how wireless works. It's fine for casual web browsing and simple things like that, but it's gods awful for anything requiring multiple connections.
Save your money, and don't bother with this if the intent is to use it with the Wii.
While searching CNET for wireless N Adapters for my Wii I found this article
http://news.cnet.com/8301-17938_105-10082437-1.html
First question:
If I plug it into my Wii, will it receive the N signal being broadcasts from my N router? Or is it an adapter that sends an N signal to the Wii once plugged into the computer? This idea seems to good to be true that a simple USB device will allow my Wii to pick up a Wireless N signal.
Second Question:
If it is a receiver, how well does it work and how easy is it to set up?
Thank You for any help.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic