Is the new iMac a pro machine?
My pal Laurie Jeffery is a bit of a gear-head and a busy professional photographer. He knows what's good. This guy is now using one of the new aluminium iMacs for his main machine (The 24-inch model I'm sure.), and he loves it. *
And Laurie is not the only one to be in doubt about the alleged "amateur" status of the new iMacs.
*I once told him I almost bought him an Apple Cinema monitor for Christmas, but I decided that he "would just be embarrassed by such a display".
I am not sure I understand the question. But clearly Apple sees the iMac as a consumer product. That's why they have a separate Mac Pro line.
Whether you can use an iMac in a profession successfully is a different matter. It's certainly very usable for writing software -- even if not in the specific field and style of programming Alex is involved in.
On the other hand, in the field of music production it's generally not considered "pro" because there's no PCI expansion slots. But you could still use it for many music production tasks in a professional manner.
When it comes to editing and retouching of photos it's probably not considered pro because you can't change the monitor (as I understand, current LCDs still are lacking in gamut compared to high end CRTs). Of course you could always add an external secondary monitor for colour proofing.
The difference between an iMac and a Mac Pro is the same as that of a compact camera and a DSLR. Your question therefore is like asking whether a compact camera, say Nikon Coolpix P5100, is a pro camera?
I beg to differ. I the (meant to be rhetorical) question is more kind to asking whether the Nikon D300 is a pro camera. Which I tend to think it is. And interestingly, it is descended in a direct line from Nikon D100, which was definitely an amateur camera.
Of course there are no final answers to these questions, since it all depends on where you set the lines. But the lines are clearly moving up continually.