As far as business goes, they have these engineers who designed xbox and 360 who are done with their current projects. Now they have to start designing something new. Like a car manufacturer, they will spend the next couple of years tracking how well the 360 is going, where it can be tweaked, what can they do better next time, and what new tech can they use. Then as the market shifts they start building the better box. These things take a lot more work than whipping up some cad drawings and sending them to a factory (not that you said they would, but sometimes people don't realize all the background work that goes into stuff like that).