If you have been following some of the topics on this forum about comparing cameras lately, you should know that there is not a correct answer to this question for every person. I suspect that each camera and each class of camera made by Nikon and Canon could have arguments supporting both and in the end would be purely subjective.
You can get the specs from each of the Mfgs but that is only going to give you marketing numbers that probably will not answer the question asked. Fortunately, the major brands are good enough you really cannot go wrong. You pick the camera system (bodies, lenses, accessories) that feel right. The weight, shape, eye position, ease of use, available specialty lenses you want use(macro,tilt shift,defocus and so on), and service policies are more important considerations.
The manufacturing tolerances used by the makers is wide enough that in most cases a given Canon model may be better that a given Nikon model but the camera you buy might be the one that is not quite that good. The same applies to Nikon. In other words it is a moving target and you will have to test and learn the weaknesses and strengths of whatever one you get. All of the published tests, all the calm and not so calm discourse on this and other forums is just a starting points that you can use to do the tests to learn your specific equipment.
I shoot a Nikon D300 and I like the metering for both flash (I use an SB800) and non-flash but that does not mean that a comparable Canon model would not do just as well especially once you learned all its little tricks and traps. I am just learning about what the SB800 and the D300 and the little surprises that I am sure will crop up.
If flash, especially multi flash (not mutiple studio flashes) is going to be important to your style of photography then Nikon's i-TTL and 1,005-Pixel 3D Color Matrix Metering II probably has a edge on most of the other mfgs. It is however only available on the higher end cameras (D200 and higher)
Have fun
Tom
