Let me also add my two pennies here...
I've been taking pictures with both cameras. Canon isn't bad, but it feels really "plastic", while D70 body is much better. Not really "rock-solid", but much closer to that. Lens quality in the kit for both cameras have big difference, i.e., Nikon's lens is much better, both optically and phisically. It locks on focus much faster. When my friend who owns Canon EOS 300D (Rebel) tried out D70, almost jumped after the first shot and immediately looked at the lens - such was his reaction at superiority of Nikon's lens. 300D lacks flash compensation, and comparing to D70 is much slower both at startup and reviewing taken images. That said, Canon's CMOS technology gives less noise, although up to ISO 800 there is not big deal, asif you shoot in RAW, there are lots of programs to reduce noise, even almost eliminate it. So we can talk about any significant noise only on images taken above ISO 800. There Canon's images will be a bit smoother. All in all, in my opinion Nikon's effering is much better, although little bit more expensive. Nikon's body feels better in my hands and I like Nikon's button layout better. Nikon SB-800 speedlight is very good too. If I could rate Nikon D70 at 100 points, Canon 300D would get 90 points. As I mentioned - Canon lacks flash compensation (real minus!), Canon 300D lacks top LCD screen, its body feels less robust, it's slower, the only advantage over Nikon D70 is Canon's sensors have better signal-to-noise ratio. So the closest competitor to the D70 will be Canon 350D... (If Nikon won't introduce new camera body)