Gamasutra has an interesting — if dry — analysis of a variety of sales figures from Nintendo's investor presentation. While targeted towards a particular audience, the variety of graphs and pie charts illustrate what's going on in the global marketplace: handheld and console sales, as well as first- and third-party software sales, shed light on how Sony, Microsoft, and Nintendo are doing across the board. Of particular interest are the figures on the European market, which tends to be difficult to get a grasp on:
... the Wii's dominance in the United States is equally true in Europe. In both regions, Wii sales are significantly higher than the combined sales of both the Xbox 360 and PlayStation 3. Microsoft and Sony have gone back and forth in public statements over which company's HD console is ahead in Europe. While recent price breaks on the Xbox 360 have probably changed the dynamic significantly, it is worth taking stock of the data reflected in the graph above. For the 9 months of sales shown in each year, the Xbox 360 appears to have had sales of around 2.1 million systems since 2006 and the PlayStation 3 has garnered sales of over 2.2 million systems since 2007. However, these figures are just for the U.K., Germany, France, and Spain, so they do not cover all of Europe.
Worth a read, especially if you're a statistics geek. The Mushroom Growth Plan: Inside Nintendo's Numbers [Gamasutra]