Dan Frakes at Macworld makes an excellent observation about the Mac Pro vs. the rest of the Mac Lineup:
This all might sound like I’m disappointed with the new Mac Pro, but that’s not the case at all. On the contrary, I’m just especially impressed by the rest of the Mac line. I think it’s fantastic that people like me, whose needs are considerably more demanding than those of the typical computer user, but not in the realm of a professional-app user, no longer have to splurge on a Mac Pro. The new Mac Pro is a pretty great computer. It’s just no longer the Mac for me.
For a long time, the PowerMac G5 coexisted with the PowerBook and iBook G4 range. With IBM unable to provide a working mobile G5 processor, the PowerMac was always the ultimate computing machine with the iMac serving as a clear middle offering with its less powerful G5 processor range.
After moving to Intel, the gap between desktop and laptop closed so much that Apple even used the same processors in the first Intel iMac, and has done ever since.
Thanks to these advancements by both Apple and Intel, the lines have blurred so much between the entire Mac family that an iMac or even retina MacBook Pro are true powerhouses. It’s not that the Mac Pro isn’t much faster than the rest of Apple’s offerings, it’s that they are all so powerful that there is no longer a huge divide between them.