|Aye they're quite comparable in most ways. I find the 'standard' settings on Nikon cameras to have more saturation in the reds, greens and blues than Canons do but that may have been the D80 (?) I tried in the store before i got my XTi.
They're also comparable in terms of lenses too and seem to do the same focal lengths, aperture settings for around the same price.
I have heard Nikon's fit a little better but i have had absolutely no problems with the Canon, it fits my hand well, even though it is pretty small without the grip and I've held it throughout a 4 hour wrestling show, at ringside, running around everywhere, taking 1000 shots with no trouble whatsoever with focussing, shutter lag or image quality.
But for $1500 you could get a decent amount of kit, even a 40D with that money. I'm sure I've seen them for $1100 somewhere online...