To all the people complaining about the lack of iMac updates, spare a thought for those who need a Mac Pro to make a living. At least the iMac saw an update last year.
It would be pretty reckless of Apple to update its entire computer line in the same period putting a strain on supply, manufacturing, transport etc.
Furthermore Apple laptops, especially the Air, are what sales best in the computer range, followed by the iMac.
I choose to believe that the iMac will probably get an update in a couple of month, but I see a couple of issue with Apple's desktop range...
If the Mac Pro has a future it would need a better GPU supply from AMD & Nvidia, who sell only a handful of their range adapted for the Mac platform.
What would be the purpose of Apple financing Mac specific version of some GPUs (that would then only be available trough them) if the end user wouldn't get the upgrade options he payed for?
Then there is this Retina future that seems to be promised to us...
I think we might see the same kind of introduction for desktop computer, meaning that when the iMac range is upgraded we'll get a Retina iMac, or iMac Pro that would have components closer to the pro needs allowing it to recuperate part of that market.
Anyway for the Mac Pro range to remain, Apple needs to provide their own GPUs, and probably a Retina Thunderbolt display, so that market becomes more R&D expensive, not certain Apple thinks its worth the trouble.