Analysts estimate that Nintendo is missing out on $1 to $1.3 billion in sales this Holiday season because they cannot satisify demand for the Wii console.

Apparently Nintendo still thinks they didn't do anything wrong. Sure it is difficult to plan production volume, but Nintendo struggled the whole year to meet demand. The demand never stopped outpacing Wii availablity over the past year.
It looks like Nintendo did not see or did not want to see the size of the demand.
Nintendo sold 981,000 Wii consoles in the United States in November, which marks the best month as of yet.
More details in this new NY Times article.
The NY Times article also has a good tip to get a Wii at MSRP. Know when the UPS truck comes to your game retailer and be there!

Wii Online:
Wii on eBay
Wii on Amazon