Canon dropped prices in December apparently due to the horrible fourth quarter sales, and resultant higher than normal inventory. You can read all this in their FY 2011 report. Canon needed to rack up as much in sales as possible to help ease the bad news to stockholders for year end profits.
Nikon is in much worse condition, having lost a ton of money last quarter, which was the third quarter for them.
The earthquake and Thai flooding last year really hurt sales and income for a lot of businesses. Canon is expecting continued poor sales this year, but has raised prices anyway. Nikon is forcasting better times, but then, they are starting in a much bigger hole.
Nikon may have a fire sale in March, since their fiscal year ends march 31, but I assume that short of really poor sales, prices will continue to go up this year. Of course, we will still see the rebate sales, etc, but they will not match what we saw in December.