The wii needs alot of things and this can all be achieved through firmware updates and regualr updates.
-have gamertags (with friend codes if Nintendo is still stubborn)
-when pressing the home button on the wii, have a online menu similiar to xbox live with friends list, messaging, and recent players that you request friend codes from.
-headset or keyboard
-make it so the Wii is compatible with usb harddrives.
-Media Channel: music,movies, and pictures from hard drive or sd card.
-Demo/trailer Channel: play demos and watch trailers.
- Make some virtual console games online
-need: more sports games, online fps similiar to MOHH2 controls, less mini games, online co-op adventure games.
- and please 3rd partys at least try to make good games.
-make Miis more customizable