In the price range where you're looking (sub-$1000 dSLRS), I would focus on Nikon. Canons don't start making sense until you're in a higher price bracket. Also, Canon's 18-55mm kit lens sucks. Unless you opt for the more expensive 17-85mm IS kit lens, it's better to buy body only. What makes the Canon EOS line appealing is their lenses. If you have plans to buy a lot of glass in the future, Canon is the obvious choice. Especially if you like fast primes (24 F/1.4, 35 F/1.4, 85 F/1.2, 135 F/2 etc) and quality zooms (pretty much all of the L zoom series). Knowing what I know now, and were I in the market for a dSLR, I'd be looking for a heavily discounted Canon 5D (mk I). For most people, I'd suggest a D90 or D60.
Be forewarned, the D80's light meter has a mind of its own. It's infamous for overexposing in most situations, and underexposing when you least expect it. That said, it's a nice camera if you don't mind continually chimping (looking at the LCD) to check your last shot. My friend Archie [photos NSFW] has one and loves it. He generally shoots in a controlled environment, so exposure issues aren't a problem for him.
If you look, Adorama often has deals where they include two lenses with Nikon bodies. Archie spent a long time on the phone with them, and got the D80, the 18-55mm VR and the 50-<mumble>mm VR in a package deal. They might be less willing to offer a similar deal with the D90, as it's a much newer body.
