Everything has probably been covered already, but...
Evidently, you would prefer an APS-C sensor, so I will not mention full frame cameras for long, except to say that if you "truly" want full frame, but are afraid it will be too expensive, don't let price be a deal killer in this area. Used Canon 5D's are very affordable, and are a very good bang for the buck. If you want full frame, but are afraid you cannot afford it, that is your camera.
The most important things to consider IMO are:
1) How comfortable is it to use the body? You already are used to Nikons, so you won't have much of a learning curve going to any Nikon. However, I find Canons easy to pick up on as well. Renting or borrowing for extended periods is a good way to get the feel of a camera in use. You are used to a Fuji and a Nikon, but should try a Canon before buying something, IMO.
2) Lenses. A camera body is just something you require in order to use the lens. Don't put too much weight on the importance of a camera body. The lenses are the heart of any camera system. In the end, I feel that they are 90% of what matters, technically speaking. So, assuming this is true, it would make sense to spend 90% of your money, and 90% of your time/energy comparing/shopping, on lenses, not bodies.
As far as lenses, Nikon holds a total advantage here in the backwards compatibility to manual focus lenses department. That is to say, Nikon has a ton, and Canon has none. As long as you do not want autofocus, going with Nikon digital can save so, so, so much money on high-quality glass that this is reason enough to never consider Canon again. OTOH, if you really do want and rely on AF, then there really isn't much difference between brands in this area. I would give minor advantages to Canon in some areas (super fast 50mm and 85mm, for example), and minor advantages to Nikon in others (105mm DC lens, for example). These are MINOR differences. But if you use AF all the time, there are no make-it-or-break it lenses from either company, so refer back to #1. And be sure to check out the PRICES of the lenses you see yourself getting. There can sometimes be huge differences between certain equivalent lenses made by Canon and Nikon.
3) The rest of the system. What sorts of accessories do you need to do what you need to do, and how much will they cost you? This also encompasses #2, lenses. There isn't much difference here between Canon and Nikon, but if you have any very specific requirements for what you shoot, be sure to compare the prices on the needed accessories! Check out what flashes will cost you, synch cables, cable releases, batteries, you name it.
Again, do not spend a lot of time obsessing over what camera body has what features. Just get one that feels right control-wise, and that makes a big enough file for what you need to do. It should be 10% of your total investment in a system, because it is 10% of what makes the image what it is on a technical level. The real deal in almost any image is the lens.
My feeling is that until the D3 and the line of related cameras after it came out, I was terribly frustrated with Nikons. I liked using them in terms of control, and at low ISOs, they were just as good as Canon, if not slightly better in terms of color. But Canons simply cost less, and had "usable" high ISOs, which I use a ton of the time. Not to mention that their lenses are superb, and pretty affordable. I did not consider Nikon's high ISOs usable, and I even like a bit of grain, so I am not that harsh of a critic.
And when the D3 came out...I was terribly frustrated with the price! Luckily they got smart and brought in a camera to slaughter the 5D, the D700. Regular sized body, pretty affordable, extremely well built, much better autofocus than 5D, etc. It was perfect for me, so I just got one (used), after using Canon digital since the 1D (Mk. I) and 10D. Nikon finally came out with the camera I wish they had made these past years. I can finally take advantage of a digital camera that takes old glass, has usable high ISO speeds, is built to standards that I appreciate, "feels" like a film camera, and is affordable, without going overboard in terms of image size. (Huge files are a peeve of mine. If I want huge image, I will shoot film! With digital, I just need a decent generally-capable image size.)
My D700 is still in the mail, BTW, though I have often used a friend's, which is why I fell in love with the camera.
Still, I am such a hater of the consumer digital nightmare cycle that has come into place, that never would have made myself get the D700 if it was not for the somewhat ignorant and practically-meaningless resolution requirement imposed on me by one of my wedding bosses. She said my 6 Mpix 10D was no longer good enough; I needed something in line with her 5D's (Mk. I's). If not for that, the 10D (my only remaining digital camera, as it is the all-around favorite for me out of the ones I have had or used) would have only been replaced when it totally died.
Eventually I will give the D700 a partner: D300s. Since I generally do not like using zooms, I nearly always shoot two cameras when shooting small format. I like small sensors for telephoto use, and it nearly exactly matches the D700 in resolution, which I find AWESOMELY convenient. Video capability may get used once in a while, but it is not a selling point for me. I want the S over the plain 300 because due to a few small (but major) control differences, it handles more like the D700, which will be more convenient and less confusing for me.
