I could have written this same post a few years ago. I had a nikon coolpix as well and it nearly drove me insane with the blurry pics and how long it took to record images. Grrr!!
I upgraded to an entry level SLR. I got the Nikon D50. Oh I LOVE that camera. I got literally thousands of beautiful pictures with it, and I learned all the ins and outs of how to work a camera without spending the big bucks and knowing if I'd like it or not (I Did!) I just upgraded to a Nikon D300s and couldn't be happier with having made that jump into SLR.
The good thing about entry level SLR's is that they have auto settings on them as well, so when you can't be bothered with manual settings you can always let the camera do the work for you. But, I promise you will NEVER regret the SLR.
Now as far as which camera, that all depends on you. I'd suggest going to the store and getting a good feel of the Nikon vs. Cannon and which you like better. Once you pick one side and start buying lenses then it's a lot of money to switch again. BUT, both camera's are equally just as awesome so it really is what feels more comfy to you.
But yes, SLR is THE way to go. Good luck!! :)
mom of four....
I have no greater joy than to hear that my children walk in truth. 3John 1:4