its a problem for nintendo but its a great problem to have. sales will decrease after new years and they may be easier to find them then but im sure nintendo isnt too upset about the supply issue
the more the shelves are empty the more publicity they get(free mind you) and as xyrax mentioned they are selling more consoles than anyone else ever has in a first year.
its a great problem to have......
I want wii fit and I want it now