I have to weigh in on this, because aside from Video Games, I've worked in business journalism as well. Sony has the muscle and the talent to continue their reign as the 800 pound gorilla, but they are more vulnerable than usual at this time.
Last year, Sony as a corporation lost about a $1 billion (it came down some after accounting adjustments, but it was a large loss). Though Sony Computer Enterainment of America, the PlayStation branch, is treated largely as a separate and singular entity, their cash flow will be monitored closely.
Now it's true that consoles do not, in and of themselves, make money. Microsoft, Nintendo and Sony all lose money on each unit. BUT, there is only so much they can lose per unit before it becomes unbearable (Microsoft's cash reserves in this case makes it formidable). Sega lost nearly $200 per unit during sales of the Dreamcast, and that forced them out of the business entirely. Sony, meanwhile, is proposing to sell a console that includes a Blu-Ray player that this summer will retail for over $1000 on its own. If they include an HDD, selling a console for $500 or lower may actually hemorrhage the electronics giant.
Sure, a $600 system that will be incredibly scarce during the holiday season will still sell to the hardcore early adopters, but if that price point remains after the holidays, a lot of people in the States, the casual shoppers and less-than-hardcore gamers Sony will have to reach once again, will find a hard time justifying such a purchase particularly if things like fuel and consumer prices remain at record levels during the summer. Nintendo, offering a less-expensive alternative to either next-gen platform, may reap a small bump in its market share come this Winter.
In essence, I think Sony will continue to hold the number 1 market share when its all said and done, but it'll be a harsher, pit-fight between it and Microsoft this time around. Capitalism is as much a marathon as a baseball season is, so only time will truly tell.
Post Script: It will also be helpful if Sony avoids the glitchy, hardware problems the 360 had this past winter, but that may be asking a lot since Sony has a loooong reputation of putting together shoddy hardware components (both my first PS1 and PS2 purchases had to be returned because of an irreparable Disc Read Error).
