How does having less cables effect the outcome of your work? The answer is none.
Apple's marketing with the imac promoted cable reduction. They always displayed it with a wireless keyboard and mouse, so that the only cable would be the power cord. That was all it was designed to be. Also there are a number of audio guys on here. Any of them can tell you that it's not just PCI slots for their protools cards. The Mac Pro also provides a silent solution. External boxes are not silent. You'll still need one for backups, but it can be powered down when you are working (as no one backs up in real time) providing a silent work area.
Thanks for the heads up on this. You make some really really good points. Personally I am just the type of jackass that would have gone right out to buy something like this. So guidance is very much appreciated. Now I have a healthy bit of skepticism about it which is a good thing.
I know from buying bad products in the past at times

. It can be hard to find accurate information. PCI cards seem like a geek solution, yet they're simpler than having way too many boxes lying around. The imac really was designed for a different era. It wasn't actually designed so much for people who make their living from Apple products. It was leveraged into that space. I've seen photographers use them, but I've never seen any use them as a primary computer. I'm sure that exists, but it isn't an ideal solution. It's more like a good enough solution out of a given product pool.
I've tried to work on that display before, and compared to what I am used to, it is just so annoying. For detail work in 3d modeling, photography, retouching, graphic design, color grading, etc. you want subdued lighting. Office lighting is awful. You get it as dim as possible where you can still comfortably walk around, and tone the display brightness down to a level that best matches the other devices in your workflow. Usually when I see someone with an imac, they're not only using that display, but using it with the brightness somewhere near maximum and set by eye in an office lighting situation. The difference between one and the other for doing critical work is just ridiculous. None of them understand that until they're shown the difference. Usually the theory is that it's better than their laptop, and none of them even remember crts (although I don't miss the flickering).
On the one hand, I could see something like an enhanced Mac mini (shades of the xMac) taking the place of the Mac Pro .. however, the paradigm is that it would rely on Thunderbolt for the individualistic customization to various applications via a pile of external boxes.
External boxes .. cables ... ugh! Wasn't this why we got the iMac in the first place?
And while this does sound technically viable, let's take a case study.
What we often hear is a comparison of s a 27" iMac i7 versus a Mac Pro with Apple 27" LCD display, which works out to roughly $2000 vs $3500.
The basic theory with this stuff really isn't that complex. You internalize parts where the compromise is minimal. You only build outward when it solves a problem that can't feasibly be worked around internally (including if something costs too much to build). The mac pro is capable of acting as a catch all for a lot of demanding users, and most of these PCIe cards are tested on Mac Pros if suggested for use on a Mac. On displays, I have two in front of me. If I connected an additional Cinema display (can't use the TB display) or set up an imac beside them, you'd see the difference. Everyone can call the imac display beautiful all they like until they try this

. Also one of these is roughly five years old with some ridiculous number of hours on it (not my primary display any longer). It no longer looks perfect, but it lacks the issues I've seen in every imac of comparable age, almost none of which will be solved by simple software profiling via colorimeter device (purple edges, uniformity completely gone, weird saturated greys, etc.).