If you are taking a poll, it's not scientific.
I purchased a Mac Pro to replace my 9-year-old G4-400 (Sawtooth) that I had upgraded with a 1GHz Sonnet processor upgrade and 1.5G of system RAM. I purchased what was the fastest Mac Pro Apple makes, because I believe it's a good idea to buy as much processor you can afford because it will last longer.
I dropped some $7,000 on my new Cheese Grater along with an Apple 24" Cinema Display.
Last fall, Apple released a new iMac that gave me pause. It contains a Quad Processor and it runs faster than my Mac Pro. With the same sized hard drive and the fastest processor Apple makes, it costs $2,700, which means I could just about purchase three for the price I paid for my Mac Pro. And the monitor's free. And it's bigger. And it's better technology.
I'm not suffering from buyer's remorse -- I like my Mac Pro. It has room for four internal drives and I have two that run in tandem, a 1.5T drive as my Time Machine backup, a 1T drive for my boot drive and a spare 1T cloned drive. Video is on my array.
If you are doing video applications, a Mac Pro gives you the expandability that you need to get the job done. And if you need a monitor that Apple does not sell (and they do sell good ones), you need a Mac Pro. But if you are doing anything but the most demanding of applications, the iMac is a really great value.
If all I was doing was design work, I'd get the 27 inch Core2Duo iMac. Occasional video with that, the Quad Core iMac. Heavy duty video where you must have an external array and you must have a cloned boot drive as well as a backup of everything, the Mac Pro Cheese Grater.
But that's an answer that really is a question: What are you doing with your Mac and what do you plan on doing? I have edited on Core2Duo iMacs and MacBook Pros and they work just great. But you should keep in mind that Apple's Final Cut Studio applications are still 32-bit applications with access to up to around 2G of system RAM. If you have Motion, Final Cut Pro and Color all open at the same time during your project, you're looking at these applications consuming 6G of system RAM. And these three applications will each use as many processors as are available (though I think Color may be using your GPU a whole lot, instead).
Apple won't make a version of Final Cut that doesn't work on a MacBook Pro. They realize they sell computers that way through their software and there are a lot of copies of Final Cut all over the world working away on their portable Macs in far off locations cutting down raw video for satellite feeds as well as editing outright in the field. But if you're editing a film project, using RED Cine, you should consider something more capable of handling, rotoscoping, compositing and editing really large images on monitors that can display the full color gamut. And for that, you need a Mac Pro.