To be fair, i think (based on no facts) that at least part of what has driven Mac laptop sales is the innovation in the line in the last few years and how far ahead they are of most other laptops in their class. Retina MacBook Pro, MacBook Air, and the fact that they seem to actively advertise the MacBook line. The desktops haven't had anywhere near as much attention. No where near as much effort, and definitely no where near as much advertising. The iMac hasn't had a major redesign since 2007, the Mac Pro with the exception of the PowerPC to Intel changeover has not been majorly redesigned since 2003(!). The Mac Mini has seen a little bit more attention with a recent redesign, but nothing groundbreaking. You can't say that the current iMac or Mac Pro is way ahead of any PC in the same price range at the moment can you? The Mac Pro especially!
If Apple really put the same effort and advertising money they put into the iPhone, iPad and Macbook line into the desktop Macs, i think the sales would increase substantially. Introducing them at Keynotes instead of silently updating them wouldn't hurt either! Remember this is the same company that made the iMac G3, G4 and G5 all within 6 years, which were all complete groundbreaking redesigns. So far the current Aluminium design has been around for 5 years. Yes they've brought out bigger screen sizes, but that's about it!
Considering how big Apple is, i really don't understand how they can put so little effort into a part of their market which on its own is a Fortune 500 company.
And the iMac put Apple back on the map.
