Marokero brings up some excellent points in his post. He gave me some good advise when I was looking at the D100.
Jeff, as far as noise goes, 99.9% of the people who see my pics wouldn't know "noise" if you pointed it out to them. (I don't mean to sound like a smart a$$, and I'm excluding those on this board). They see the pic and like it or don't like it.
Your statement "Is an amateur like me going to see a qualitative difference between images?". Maybe, maybe not. Probably after awhile you will. We're all different. However, I've noticed a difference in my images from when I first started using the camera up to now. They've gotten better. All because I'm still learning the functions of the D100, and pick up a ton of pointers from the people here. The best part of it all is that your not wasting film. So if you take a pic and don't like it, delete it!!!
All in all, both cameras have their little faults and also, more importantly, their good qualities. IMHO, it's a ten point toss up between the 2. You won't go wrong with either one. As for Nikon releasing a newer digicam........there's rumors of it happening......I'm not holding my breath, only my D100