I haven't read any statements about this before, so my comment might not be valid. However, I think we should take into consideration that Sony's fiscal year starts April 1 and ends March 31. Meaning that if the PS4 has a world wide release sometime between October and December, it will actually have a sale period of 4-6 months this fiscal year.
Taking earlier systems into consideration (mainly N64, PS2, Xbox360, PS3 and Wii), a reasonable production capacity in the beginning of a presumed popular systems life cycle is 1 million units/month. In rare cases, it might be possible to reach a slightly higher figure. This would put PS4 sales at around 4-6 million systems this fiscal year. Anything beyond that would be mind blowing.







