The companies would point blank stupid to try to force another generation on us now, with the economy the way it is.
Plus as stated before the PS2 (as well as the PS1) has some major staying power. So I would agree that PS3`s cycle will be extended even more, Seeing how it is utilizing the bluray, is updated frequently, and the HDD is easy to upgrade. I would think the latter two also apply to the 360 but I dont have much exp. with it.