I am not really sure what's driving this slowdown - Obviously desktops are being replaced at a much slower rate - they are good for four to five years (easily) for almost everyone nowadays. I wonder if laptops are also seeing longer than their traditional 24-30 month lifespans.

Are tablets/smartphone really impacting desktop sales? I don't see too many people out there who've replaced their laptop/desktop with a tablet, but maybe they are holding off buying a new laptop as quickly, and spending that money on a tablet? Maybe some people are getting by with a smartphone in place of a laptop every two-three years?