Simple...Its not.
The cost difference will continue.
This year least costly 360 will be $200, PS3 $400
Next year least costly 360 will be $150, PS3 $300 (maybe)
2010 least costly 360 will be $99, PS3 $200 (maybe)
Blu-Ray will advantage will decline as the price of stand alone players continue to drop.
3rd party games will not be an advantage for PS3 the remainder of this generation.
1st party games will be a wash between the consoles.
As for this year. The PS3 will stop showing year over year increases come November. This because the price drop to $400 happened the beginning of last November.
Its libraries that sell systems not a single game.







