@ZorroX Sorry, but Xbox 360 only selling 1,5 million consoles in the Americas isn't a worst case scenario, it is an impossible scenario. The only way it can come true is if Microsoft decides to withdraw from the gaming market. But then you can put 0 consoles sold as a worst case scenario for all platforms.
As for Others, there is no different market for Xbox 360 and PS3. They're both part of the same market being very close substitutes of each other. So if the market is really saturated they're both going to have a hard time selling their consoles, not just Microsoft. If you want to argue the brand power of Playstation is a lot higher than Xbox in Europe you have a point, but that's not the same as market saturation.
All in all I feel your Xbox 360 numbers range from disaster to worst case scenario and your PS3 numbers range from normal to incredible scenario, so basically a very unbalanced view.