Buy a Camera Body, Not a Camera System
When I first became interested in photography and SLRs something I regularly heard was to consider the camera system you were buying into, not the camera body. Which manufacturer makes the lenses you need, especially if you need tilt-shift or macro or bellows, for example. A camera body is just a box to hold film and its features should be a secondary consideration because manufacturers are always leap-frogging each other. Photo.net's Building a Digital SLR System page says it:
First-time consumers of digital SLR cameras focus on the body. Long-time photographers, however, look at the system. An SLR system includes a body, multiple lenses, flash units, and various connecting cords. For most photographers the investment in lenses will come to dwarf the cost of a body. It is thus important to choose a system whose manufacturer makes the lenses that you need for all of your potential projects and, ideally, whose system is popular enough that you can rent special-purpose lenses for uncommon situations. Each camera system has its own lens mount design and a lens that works on, say, a Nikon camera cannot be attached to a Canon body.
Having started with Nikon film cameras and switched to Canon for digital, I feel I can say with some certainty that this is a bad idea.
Background, in case you missed it: my 20D needs a repair so I am weighing camera options. Basically, the 20D repair bill isn't worth it, I don't think. So I need a new camera.
Since switching to Canon several years ago I've tried to learn that equipment as best I could. It started out rocky because I would "think Nikon" and go to press a button that didn't do what I thought it did, for example. It didn't take long to get over that. I read the manuals many times over, I shot, shot, shot, and have become comfortable with the Canon gear.
That's something that has nagged me for the last two-plus years: I'm comfortable with the Canon gear. Shouldn't I know it intimately by now? Shouldn't everything be automatic, where changing the ISO or flipping autofocus off is simply second nature by now? I thought it should. Try as I might, I haven't mastered my Canon equipment. Not in the same way I knew my Nikon cameras. Is that because I've had more years of experience using Nikon equipment? It couldn't hurt, but I've used several Nikon bodies with different interfaces.
Now, with a busted Canon 20D, I'm presented with the opportunity to buy a new Canon body... or switch back to Nikon. Switching to Nikon is an attractive option because any time I handle a friend's, I feel comfortable with it. I know it. In particular, handling the D2x, (and most recently the) D200 and D300, it's just like my old F100 film SLR camera. "Muscle memory" kicks in, and I know what to do. Being digital SLRs they're very different so I don't want to say "I've mastered them" after just a few minutes of use, but I do feel more comfortable with them than I do with my Canon gear. Even the D50 and D40 are comfortable and familiar. With Nikon, I'm at home.
I think having exclusive experience with both systems puts me in the lucky position of being able to recognize some of the differences and similarities that might be lost on somebody who uses both systems day-to-day, as well as at an advantage to those who don't have enough experience to make a choice. And so, my two cents:
The camera system doesn't matter, the body does. For most photographers the basic choices are the same from either manufacturer. Want a mid-range f2.8 zoom? Check. Cheap(ish) telephoto? Check. Wide-angle prime? Check. Wireless flash system? Check.
The camera body is awful personal. Finding something with the features you want or deciding on what you want to pay can be hard, sure, but recognizing what you'll be able to learn and enjoy is ultimately more important. Do the curves of the body fit your hand? Are the buttons too small or too hard to push? While holding the camera to your eye and reaching for the shutter release, does it fall just where your finger expects? Do you hit buttons by accident?
Take note of these things when searching for a camera. Buy the body that feels best to you, and build a system around it. That's what I'm doing. (To be clear, I'm not advocating changing systems any time you need/want a new camera body. Just that the importance of finding one that fits you is largely undervalued.)