I've been a professional Motorsports and Amateur Sports photographer for years. I've had more gear than I could possibly remember, but now I shoot Nikon. But I took just as many great shots with my Canon and Fuji rigs, the only difference is how easy it was taking those shots. I've found Nikon SLR's faster and easier to operate, the controls just make more sense.
But if you're not considering a D-SLR I don't have much advice I could give, other than get whatever reviews well on dpreview.com
So, it kinda sounds like you're considering a D-SLR ... are you? If so go to your local store and fondle both Nikon and Cannon. Go through the process of taking a couple test shots, reviewing them, deleting them, and taking more. Try changing settings too. Just see which one handles best to you. It honestly doesn't matter what model number you handle, the Nikon and Canon user interfaces are pretty similar across models. I would suggest NOT getting a Nikon D40 though, having no focus motor in the body is big potential limitation. Honestly, I'd get a used D70s and you'll still have enough cash for a couple lenses.