When the Wii was first release all it needed to sell it was the fact that it had motion control to interact with the game. In the passing years, it has been reported that about 60% of all Wii owner don't play there Wii anymore. There's a good reason for this, here are some of the things that Nintendo can do if they want to improve the Wii to compete with the Xbox 360 and Playstation 3.
1. DLC (There's no reason that the Wii can't have DownLoadable Content. The Wii lets the user to use up to 32gb SD card for storage.)
2. Play DVD ( Nintendo had stated it would take more then a firmware update to play DVDs; but hackers of the Wii prove this wrong. Nintendo also stated that the Wii is gaming system and not multimedia system, Nintendo needs to redefine their system now that netflix was release on it.)
3. Online Gaming (Sure the Wii has online gaming; but its crap in compressing to the Xbox and Playstation. With no setup servers on Nintendo part, online is left up to the manufacturer of the game.)
4. Exclusives (Probably the Wii has the most exclusives games on the market to date, but their crap. Nintendo take a page from Microsoft and Sony's book and throw some money at game manufacturer to get some great game on your system.)
5. Give a dam (This point ties into my last point, my Brother and I feel that Nintendo has attitude of just not caring who manufacturer games for there console. Nintendo mono is if you manufacturer for are system that great and if you don't, will we don't care.)
There's a bunch of thing the Wii can do, only if Nintendo took time and money to work on it.