what happens if you hold the eject button? Just thinking I have a dvd player, that if I hold the eject button down, it keeps the eject mechanism working constantly.
Maybe the wii is the same? It might "catch" the disc and then send it out..
Just an untested idea
Other than that, give Nintendo a ring.
Another thought.. What position is the wii in? (vertical/horizontal) maybe try putting it in the position it isnt in.. it might locate the disc into the right area.
I think if it was me (feel free to not do this) I would unplug it console, give it a light shake to see if i can tell if the disc is loose inside, if it is, again, I might be able to "re-locate" it to the right position by shaking it lightly and twisting it to slide the disc around...