Microsoft had a year head start, but Sony is hot on its tail.
When it comes to console sales, no one can touch the Wii, but the Xbox 360 and the PlayStation 3 have long been battling it out for second place. Microsoft got a bit of a head start thanks to a year earlier console launch, but the PS3 has been catching up.
Microsoft currently puts Xbox 360 sales at 57.6 million units while Sony's latest announcement boasts a total of 55.5 million units. Nintendo, of course, is far ahead with over 89 million Wiis sold.
It seems likely that one of the big reasons that the PS3 is closing the gap is also one of the biggest differences between the consoles - Blu-ray. The PlayStation 2 found its way into many homes as a DVD player first and a game system second. It seems reasonable that the PS3 may have found a similar niche.