@RLPhoto, one other thing that factors into this is I also do a fare bit of video editing as well which I use Final Cut. Hence my need for a machine running OSX. I'm not trying to make this into a OSX vs Windows thread but there are definitely advantages of OSX over Windows 7. The hardware is definitely more expensive but my thought with the iMac is the fact that it has a quality display that made it a better value than a different Mac. I just did a quick calculation of building my own computer and I'm looking at somewhere between $700-$800 including a license for Windows Home Premium. That means I have to build it and if there's any issue I have to solve those. If I want to run OSX then it's even more of a hassle and most likely at least one piece of hardware won't function exactly right. Not only that but now I have a big tower taking up room and most likely using more power than the iMac would. Thus I would like to at least save $200-$300 off of an iMac for the inconvience so I guess the real question is, does a $200 to $300 display beat the quality of iMac display?
You can purchase a Good Dell IPS monitor for around 300$ and won't be tied into proprietory hardware.
As for video editing, If you like FCP then stick to it but don't believe that its the only option. AVID and CS5 Premiere pro run on Win Machines and are just as powerful. Windows software has been re-nouned for its longevity, just look at CS2. I know many designers that can't upgrade because they'd need a New OSX Software which they're computers can't run and so they'd have to purchase all new machines! That'd be over 12 New mac's in one company's case. I'm still cruzing my CS3 software right now.
Towers allow better cooling than the Sandwiched, laptop esque IMac. We have a few still here at the office I work at and they do get very hot.
Another Point is Murphys Law, and Mac parts are MUCH MUCH more expensive.
Its your call, all I'm pointing out is the Facts and nothing more.