"regardless of the cost price of manufacture, the decision to raise the [Wii’s trade] price to retailers in the UK was taken due to the severe depreciation of the pound. From the Wii launch in December 2006 to December 2008, the value of the Pound fell by 43 percent against the Yen." - Nintendo spokesperson

Later on in the article, we hear a bit from an analyst on a price drop. Long story short, the analyst just doesn't see that happening. You can check out the full report for yourself right here