Buying a dSLR is really not as simple as buying a camera, because you’re buying into a system. From my POV, the largest barrier was building up the capital to buy an initial body and lens, but as I continue this expensive hobby, the cost of the body (and eventual upgrades) are negligible. It’s the lenses that really get you(r money). So when you buy a dSLR, you’re really buying into a system of lenses and equipment.
As you know, I’ve bought into the Nikon system. Why did I do that? That’s a good question. For me, it was a choice of between Canon and Nikon because these are the two major players in the market; so there is at least some security that the equipment I will eventually buy will still be supported in the future. I spent most of my time browsing on Craigslist and saw a much larger number of Canon ads compared to Nikon, maybe in the 3:1 or 4:1 range, but on the street I seemed to see an equal number of Nikon and Canon users. Is this noteworthy? Maybe you can draw the conclusion that Canon users are less satisfied or feel the need to upgrade more often.
I was looking at either the Canon Rebel XT or the Nikon D50. I liked the fact that the Rebel was slightly smaller, but it was more expensive. The D50, besides being cheaper, also used SD cards which I had a couple of. I hadn’t really done a lot of research into Nikon lenses, partly because they have a lot of alphabet soup on them, but it seems that they are slightly more expensive than their Canon counterparts (e.g. the 50mm f/1.8 is 50% more expensive).
What bothered me about Canon was that for some reason, there was an abudance of silver bodies (at least on the used market). Have you seen an enthusiast with a silver camera? No, because everyone gets a black one! Come on Canon, do some market research. Nikon on the other hand only makes black bodies. Not to say they are racist though, they apparently make silver lenses which I personally have never ever seen, and for good reason.
Now, I don’t know if I’m cornering myself, because I am the only person I know that is on the Nikon system (Nelson, your dad doesn’t count). If I had bought a Canon, I could leech lenses off Aaronisian and Jeb. What Nikon has going for it is that it has a stabilized 18-200mm lens (alphabet soup: 18-200mm f/3.5-5.6 G ED-IF AF-S VR DX Zoom-Nikkor) which is the one lens to rule them all; you don’t need to carry another lens around.
Nikon has a bit of stuff going for it, but not that much. I could easily have swung for a Canon and been just as happy for now.