Thanks for your reply on my post
I can't claim the following to be any sort of "Market Research" (as a user commented above) but here goes.
I work the Apple stand at the flagship store of a well-known electronics retailer in New Zealand.
People love the iMacs, their design, their features, their out-of-the-box setup.. But, unfortunately for me, most customers are distinctly aware that these machines cannot be upgraded at all - hence a call for the dubbed 'xMac', a headless mid-range tower. And there are many people who dislike the inbuilt displays in the iMac - A photographer who needs better calibration options, for example, and people who can't stand the glossy displays.
They see Mac OS X as a huge benefit; very stable and intuitive with great software as standard in iLife 08'. Incompatibility will Windows programs is something they can live with.
For those who believe Boot Camp or Parallels are one-stop-shops for people wanting to play games - in my experience, I'd have to disagree. I've never heard of an iMac sale with a Windows OS attached, or even Parallels. It doesn't happen. Customers love the idea, but seem reluctant to realise such a setup...
End of story.... Apple, listen to the people

Historically Apple
have done this, but in a painfully slow and delicate manner. Just look at the MBA...
Perhaps with the introduction of the Macbook Air in their notebook range, Apple could also expand their desktop offerings by introducing a mid-range tower - something I'll personally greet with open arms and open wallet
Cheers