Not surprisingly, Sony is lowering the price of its PlayStation 3 console ahead of the holiday shopping season. The price of the top-end 80 gigabyte model was cut by $100 to $499. It also announced a new 40-gigabyte model for $399 -- cheaper than Microsoft's highest-end Xbox 360.

In August, Microsoft announced a price cut of its own: The low-end Xbox 360 "core" costs $280; the midrange version is $350; and, the high-end "elite" system is $450.

Sony's move comes on the same day the NPD Group is expected to release its latest market-share figures for September. This will be the first month to show the impact on Xbox 360 sales of the blockbuster game "Halo 3," which generated $170 million in U.S. sales in the 24 hours after it was released Sept. 25. Microsoft executives had expected perhaps a third of "Halo 3" purchasers to buy an Xbox 360 at the same time. Check back this afternoon for details.

Meanwhile, here's what the U.S. market looked like in August, according to NPD (the first number is August sales, the second is life-to-date sales):

Wii: 403,600; 4 million

Xbox 360: 276,700; 6.3 million

PlayStation 2: 202,000; 39.1 million

PlayStation 3: 130,600; 1.75 million