I do own and run noise reduction software, actually it's from topazlabs. Very happy with it. I just feel since i've owned my camera since 07, there is better to be had now so decided it's time for an upgrade. Noise however would be my biggest issue I deal with in low light photography so that is something I know off the bat I want to look at in my next camera.
I shoot pretty much anything and everything, it's a hobby. But the main issue is low light conditions that I would like to have a camera that will have a higher iso setting then my XTi does. 1600 is the highest setting on the XTi, and you pretty much want too stay clear of that in low light so 800 is tops so getting a newer camera that will give me higher iso's would definately help alongside my noise reduction software. I also love photographing my companions when I have them out and about hiking or walks, a Golden Retriever and a Black Lab.
As for lenses I already own, 70-300mm f/4-5.6 IS USM, EF85mm f/1.8 USM, EF50 f/1.8 as well as the standard kit lens that came with my XTi. I also own the 400 EX II speedlight. For vids is needed, which is rarely, i'd use the G11 I also own.
My price range would probally be up too 1,500 or less. I hope the more information helps I've supplied you with.