Given the choice, I would rather spend the least amount possible on the cameras and the most possible on the glass... the glass makes the image. Nikon's kit lens is better than Canon's (at least to an article I just read) but there is absolutely, positively no way I would make a buying decision based on who has the best kit lens. Cameras you will replace every little bit, but the lenses you will keep for many, many years. Choose the lenses you like, then buy a camera to match it... that's what I say.
Personally, I think the Nikon 18-135 is VERY overpriced, when for only a few dollars (less than $50) more money you can get the D80 with the standard wide-angle zoom PLUS the trick new 55-200 VR Zoom (which blows the pants off the 18-135... VR is VERY cool).
I am a Nikon guy, but the Canons are nice as well (if you forget about the kit lenses and concentrate on getting better Canon glass).
It makes no sense to me to have a nice camera body and cripple your images with cheap glass.