The biggest problem for Sony (in my opinion) is that the high price and constant promises of a "10 year plan" for the PS3 make it unlikely that Sony would be able to produce a console less than 12 months after the first console is released next generation. Now, it has happened in the past and is plausable that by the time the PS4 comes to market the leading console for the next generation could aready be decided ...
Basically, suppose that Nintendo (or Microsoft) release their next generation console in the summer of 2011 and it sells like the Wii and Sony doesn't release their next console until Christmas 2012; by the time the PS4 is released its competition could have a 30 to 40 Million unit lead on it and will have secured the lion's share of development resources.
Is it possible for Sony to come in first in the next generation? Yes, but that would require Nintendo and Microsoft to make mistakes which prevent the market from embracing them ... In other words, its not really in Sony's control
