The major difference between Microsoft and Sony with regards to gaming is that Microsoft has passed the point where it is willing to divert the huge profits from its main divisions to the Entertainment Division (which is Zune, Xbox and some other smaller projects), while Sony is willing to sacrifice far more of its corporate holdings, profit, potential for profit, really its entire strategical outlook for the Playstation (now "Networked Services" division as of Apr 2009) line because PS1 and PS2 produced a bit over a quarter of Sony's profits from 1995 to 2005.
My issue with these proposed come backs of Sony as a gaming brand center on the fact that the company largely relied on huge outside support due to favorable publishing economics to build the PS1 and PS2 into juggernauts. If you look at the Game Boy or the Game Boy Advance, Nintendo has shown it can be profitable, and sell tens of millions of systems without much third party support due to the strong cache of internal brands. Sony doesn't to have the ability to consistently deliver content internally to push hardware. I don't think your ever going to see Nintendo or Microsoft screw over developers enough for Sony to build a huge cache of third party exclusives.
I think as a rule of thumb, a system probably needs 60-80% of major third party content to offset the power of Nintendo's content, plus whatever third party exclusives it gets. If it dips below that level, or the 60-80% is "shared", the largest piece of the pie is going to go to Nintendo.
Right now if you look at software sales for the three systems you probably have (estimated through June 2009)
Wii - 390m...215m third party (45% first Party)
360 - 275m...190m third party (30% first party)
PS3 - 190m...133m third party (35% first party)
If those estimates are remotely close, you have 40% of all third party content sold on Wii, with probably 85% of the remaining 60% shared between PS3/360. "OK" third party exclusive support + Nintendo content is a major advantage over Sony/Microsoft support + "great" non-exclusive support.
Hell, Wii already has had more third party titles on it sell 3m+ copies then NES did, and NES had a 62m base - over 20% higher than where Wii is now. If Wii stopped selling completely even at 75 million, I would expect 350-400m third party games to be sold on it - and thats enough to prevent full third party support swinging to either Microsoft or Sony in the near term. At the moment it is looking like Wii will get to over 100 million in 24 to 36 months, so there should be more like 500m + third party games sold on Wii. If the attach rate gets to 10 by that time, I think Wii could end selling as many as 700m or 800m third party games.
People are difficult to govern because they have too much knowledge.
When there are more laws, there are more criminals.
- Lao Tzu