360 had a year's head start and only a 5.5 million lead on the PS3. Almost 3 years later the gap is almost 8.5 million and has increased by 3 million roughly 1 million 360s have sold than PS3s per year for the last three years. The 360 is likely to counteract any price reduction from Sony. Entry level 360 will always be roughly half the price of entry level PS3.
The PS3 is unlikely to last a year longer than 360 in order to sell enough systems to beat the 360 in lifetime sales.
The PS3 has the edge technologically wise over the 360 by having the inclusion of a Blu-Ray player and triple the number processors of the 360. PS3 games have not been that far advanced than 360 in regards to graphics. The 360 has the egde in regards to online play where a higher percentage of 360 owners use 360 online despite it being a paid online as opposed to a lower percentage of PS3 owners use there PS3 online which is a free online service. Microsoft has a lot more money than Sony and is unlikely to give away its 8 million to 9 million console lead. Introduction of a new XBox in two or three years will be the killer blow which will slow down the PS3 sales.
The game libraries of both PS3 and 360 are almost identical except for a few exclusive games on each system. The 360 exclusives sell a lot more and 360 has a higher game attach rate per console sold than the PS3.