The biggest assumption that wont pan out is that when a big title (FFXIII, GT5 or even KZ2) hits that console sales will jump drastically and consoles sales will stay high. Since the PS3 will have a large (20-30million) base of enthusiasts, particularly for those titles, already waiting to purchase them the bump in sales will be minimal.
MGS4 was a perfect example of this, sure there was a one month bump in sales of a couple 100,000 units, but nothing sustained. Look at GT5 for instance when it releases the PS3 will have about 30 million units sold. At that point if 10% of existing console owners purchase it then Sony sells 3 million units. We all know that more than 10% of existing PS3 owners will purchase GT5. So even at 6 million units of GT5 sold the new console purchasers will be minimal.
What the titles do do is hold sales rather than have them decrease. What really sells consoles at this point is a quality library that continues to grow. Sony can not take that away from the 360. Therefore the PS3 will not overtake the 360. MS execs will be pouring money into software development teams over the next 3-4 years to sell software to a console base that will hit 40 million at the end of 2009.
Its libraries that sell systems not a single game.













