I agree. The companies are very close in most terms...with one being better on some fronts but not others. For the most part, every new model that comes out, is better than the competition...so it's back and forth.
I would have said that Canon was clearly ahead, at the professional level anyway...up until the last few months...but Nikon finally released some full frame DLSRs.
Comparing them, head to head, in an overall sort of way...is just a waste of time.
If you want to compare them, I suggest that you do it with the cameras in your hands. The layout and controls will be different and the one that fits you best, might be your best option.
there is no answer to this ... usually whichever company released the most recent camera body, in that snapshot moment is leading with respect to the body. and with lenses you really have to comapre two particular lenses, you cannot compare two whole sets of lenses. both companies sell crap lenses and some fairly good lenses. Neither of them does do miracles either.
Also, if you try to compare, it really depends on what you shoot and how you shoot. what is good for one style is bad for the other.
I shoot Canon, but I like Nikon also.
They're both great systems, and if I could afford it, I'd have a full set of both. Not because it's necessary (since one is lacking), but because they are both awesome systems.
If you choose one over another, you probably aren't going to be missing out on too much.
I don't there this is a clear, definitive winner between Canon and Nikon. Not that long ago, Canon had an edge with speed, but with the D3 and D300, Nikon is pretty quick now too. And, Canon has that 21 megapixel dSLR, so if you're going for resolution, Canon is the clear winner. Overall though, to get a winner, you'd have to go specific body vs. body. XTi versus D80, 40D versus D300, you get the idea.