Sticking strictly with the Nikon/Canon debate (since the poster has already purchased the camera)....

Both cameras are the top name choices of professionals, although more professionals choose Canon more often over Nikon (never have found a study that shows exactly why though).

According to most professionals or very serious hobbiests, the kit lenses on any camera stink, although in my own opinon I don't think the kit lenses stink at all unless you are into making huge enlargements or professional pix which require a faster lense. My dad owns all Nikons (5 of them) I own all Canons (6 of them), both of us are serious hobbist/semi professional and have used the kit lenses from both cameras that have produced stunning pix. Most people will want to expand their lenses anyways to include more zoom or special use lenses. The kit lenses include the most basic wide angle and some mid range zoom for the average consumer to get started with.

D40 vs. Rebel XTi : XTI has more megapixls, D40 has higher flash sync speed beyond that they are similar. I'm told Canon's tend to have more saturation in their pix than Nikon and Nikons need less post production sharpening than Canon.

The Nikon vs. Canon debate has been going on for years and is a bit like asking what the BEST toppings on a pizza is...no clear answer.

Although I'm a Canon fan, my dad is a Nikon fan, neither of us will tell someone any ONE brand is right for everyone, it depends on what you need from a camera, how you want to use it, and how comfortable it is to operate for an individual, we just have more familiarity with the brands we are used to using.

ok that was my $.02 worth. lol