This is impossible on the Wii unless...

[16BitAlex]

...they find a way to make the Rock Band Network Channel.

Unfortunately, no one can make channels but Nintendo right?

[davidshek]

...they find a way to make the Rock Band Network Channel.

Unfortunately, no one can make channels but Nintendo right?

And even then, that still wouldn't be enough. Just having a place to sell the songs is not sufficient. Nintendo also needs a way to distribute payment to submitters, like XNA.