I laugh that Nikons have "worse ergonomics"...that's hilarious Gavjenks. Canon's ideas about ergonomics are pretty laughable. Ya' gotta love a camera that alternates control functions based on metering mode!! Canon's dumbest idea ever...but then, they decided their ergonomics and control layouts back in the mid-1980's when they dumped all their users and went EOS, and they have stuck with a system on tiny buttons that have two features per button, so the user is often left guessing, "What is this button actually going to DO when I move the wheel?"
Canon has better ergonomics than Nikon. zOMG..sorry, but I've just gotta laugh about that one!
Canon Car: Gas pedal, brake pedal--let's ALTERNATE the function of those two controls, depending on which GEAR the car is in--that is Canon's control system in a nutshell. Ridiculous. Buuut, it's all they could come up with in the mid-1980's.
This is something that doesn't really matter after shooting with either system for a week, tops. Simple contingencies are easy to make second nature, because it doesn't actually require more actions. It just requires different intuition, which you can learn rapidly.
I refer primarily to the much more crippling lack of custom settings modes that are not nearly as good as Canon's. On many Nikon cameras, you have to go into menus to call up the custom memory settings, and even then, they don't work as well. Having to go into a menu with multiple clicks, taking your whole head away from the camera, and then also having to change 3 or 4 other settings in OTHER menus (since it doesn't remember everything that it should) is not something you can ever "get used to" or make second nature, compared to just clicking one dial to the mode you need. It will always be slower, because it is many more physical actions, not just a different habit.
AFAIK the D7000 is the only camera to have finally borrowed this crucial feature from Canon, done correctly, on the dial, with full recall. Hopefully this will spread to future models in general.
Similarly, but more generally, Nikon menus tend to be much more nested and require more clicks. Unlike wheel behavior, this is not something you can ever "get used to." More button clicking is more button clicking. It will always take that much longer.
Anyway, even if you disregard ergonomics completely, the cameras are currently fairly comparable with better sensor dynamic range and such in the Nikons and better ISO performance in the Canons. Nikons offer slightly more ancillary features (like FPS) at similar price points, but then again, you have a 20% chance of having your sensor slathered in oil or your left AF points not working... Pretty much all washes out.
Obvious solution still = buy whatever you have lenses for.