The reason the PS3 is "winning" is that Sony decided to take massive loses in hardware revenue in order to drop the price. Is it any wonder that the PS3 only began to win when the price dropped in the US and Europe?
The Playstation has alot of brand name recognition, and is very popular. However, the price was (and still is) so restrictive for the casual Playstation gamer, it prevents them from thinking about the console. However, with the price dropping to $400 USD for the base model, more people can justify the purchase of the console than at the $500 base price of the 20GB model.
And in Europe, I believe the impact is magnified due to the Playstation having a much better track record. Nintendo never, ever did well in Europe before the Wii, and Microsoft did good, but not great - Sony has always done fantastic there (as opposed to Nintendo still holding well in the US, and Microsoft doing well in the US as well).
All is fair in love and business, and Sony, in the past 20 weeks, has done more to sell hardware than Microsoft has - we've seen that the Xbox 360's price drop in Europe has done rather well, but not to the PS3's level, and have haven't seen what a $100 USD reduction would/could do to the 360 in the USA.
So I think that it all comes down to cold, hard cash. Microsoft is making a killing on hardware now compared to what Sony is, but is sacrificing the 2nd place LTD sales position this generation for it....Like I've been saying for the past 2 years: Sony will win the console wars due, primarily, to good brand name recognition in Europe, and a very long console lifecycle. But not without huge costs (since this has been the first console they've ever lost money are, and probably won't make it back for another few years).
Back from the dead, I'm afraid.
