The interesting battle is going to be in Japan - the ps3 has decent sales numbers for Dragon Ball Z this week and of course MGS4 is launching where you can expect big numbers in Japan, these 2 reasons to purchase a ps3 is it's defining time right now cos it's a long wait for FFXIII and things will be decided then.
The Wii has Shiren pulling in decent figures so far, TOS is due to be launched soon and Tenchu 4 has just been announced so if TOS gets decent success a lot of eastern devs could follow suit and you could see a spade of Wii announcements in the next few months.
How this unfolds is gonna be important to how each will react in my opinion.