If you break down the sales into smaller sets and include more games you can get a bigger picture of what is happening ...
For example look at sales above 10 Million, sales between 5 and 10 Million, sales between 2 and 5 Million, sales between 1 and 2 Million, sales between 500,000 and 1 Million, sales between 250,000 and 500,000, and sales between 125,000 and 250,000 ... What you will notice is that the Wii will win in every category and the gap between the systems will be the largest in the highest sales categories, and as you get into the lower sales categories they have similar numbers.
The reason for this is simple, while total software sales for the Wii are much higher than the PS3 the number of games that are particularly good is smaller which results in a handful of games getting the lionshare of sales. As time goes on, and the Wii gets more "acceptable" games, the sales will distribute more and the number of games selling at every level will increase.
