I'm considering a Mac Mini. It's not quite what I want but unless a much cheaper Mac Pro comes out (yeah right) or a mid-tower (no rumors of such) the Mini is the only thing that will work for me.
I make extensive use of KVMs. Because people have asked I have used Avocent (they're okay), tried a few Belkins (the small 4-port KVMs all had some weird problem or another so I finally dumped them all, the 8-port KVMs were clunky and a bit expensive but they work unfortunately that model was PS/2 only) and finally settled on certain IOGears. I use the 2-port USB KVM that supports multiple architectures to switch between Sun workstations running Solaris and PC's (note that it has an issue with Dell Latitiude docks) with a Dell 2407 24" LCD. The good thing about that KVM is the cables are built-in, it supports speaker and mic switching, it can emulate Sun and Apple keyboards with a PC keyboard and it's very affordable (around $50). I really like the (expensive) 8-port GCS1758. On one GCS1758 I have run Sun workstations, Intel PC's (built on Asus motherboards running Windows, Linux and VMWare), Dell notebook PCs, Toshiba convertible PCs, Fujitsu Stylistic tablet PCs, HP servers, Sun servers and a Mac Mini Core "1" Duo with a Dell 2407 24" LCD. Works GREAT! On another 8-port I run Windows PC's (built on Abit mobos), Linux running on a PCs (built on Asus mobos), a Mac QuickSilver G4 (running 10.4 that is the candidate for being upgraded to a Mini because of the fan NOISE), the occasional Dell notebook running Windows or Linux and an Xbox 360 with a 22" LCD. That works great too. I have a 4-port IOGear that I have yet to use, but I got one for someone else who has reported no problems with it. I tried a 4-port IOGear PC that switched DVI-D and that one was kind of weird because it also switched USB peripherals so computers were always mounting and unmounted USB devices which is annoying. And the DVI port on the monitor attached to it died and when I looked on the Internet a couple other people reported the same problem which made me wonder if it was a coincidence or there was a problem with the KVM so I retired that KVM. I highly recommend the GCS1758, the only downside is that it's really expensive and then you have to buy their proprietary cables on top of that. But it's not targeted at the consumer market so that's not a surprise (relative to the networkable Avocent switches or Lantronix console switches it's inexpensive).
Given all the above an iMac would never work for me. A Mac Pro is out of my price range (it would cost more than the Sun Workstations) so the Mac Mini is the closest fit but it's not a good fit. I use a lot of disk cartridges so I'd really like something with exposed 5.25" and/or 3.5" drives but that is rare in the Apples. So I'd like a Mac Mini about three times taller than it is (a Mac Midi?) that was easier to open that could run a pair of high capacity SATA drives so I could set up partitions for a RAID 1 data volume. However a Mac Mini with external 1394 disks will work and it's a foot in the door for OS-X.
