This is somewhat odd, but Nintendo is coming out with the Wi-Fi Network Adapter [JP] for the Wii. It’s odd because the Wii works with Wi-Fi right out of the box, unless you consider going into settings and configuring your Wii to use your local network not right out of the box. This adapter attempts to solve that problem.
It can work as a stand-alone router or as a network bridge, sitting between your router and Wii. We lack the specific stats, though, like if it works with 802.11n or anything.
It’s scheduled to come out in Japan on September 18 for around $53.