SORRY!!! And I'm not a DUDE...Give me a break, I'm new to this forum. Just pass my thread's on by next time please. Thanks!
Welcome to the forum.

Since you are new, you may not know. Canon vs Nikon is like Ford vs GM, Coke vs Pepsi, Mac vs PC. You will draw a lot of response like this even if it was not your intension.
Personally, I do not think one brand is better than the other. They both have their own advantages. If ISO performance is your highest priority, Nikon cameras seems better in general. If tiny little macro world is what you are going after, Canon seems better. Someone like the way the photos come out from Canon, while other like Nikon or Sony, Pentax or Olympus.
If you already have a lot of Canon lenses, staying with Canon may not be a bad idea. It is really hard to choose one for you, you just need to find it out yourself. I like Canon, because I use Canon. At the time when I bought my first DSLR, Canon was better since most of them use CMOS sensor while Nikons were CCD. But now, the sensor in Nikon DSLR cameras seems better. So thing changes from time to time.
But one thing I know for sure, even if I change my camera to Nikon, my photos is not going to be better. It is me, not the camera nor brand.
If I were you, I will first set a budget and see what camera fit your budget. Do not just focus on Canon and Nikon. Take a look at other brands as well. Sony and Pentax are not bad either (based on what I read). Once you have a hand full of models on your list, do some research on them. Check with camera review site such as dpreview.com and see what they say.
Good luck.