Unless you really need the video capabilities .. I'd say:
1- if you stay with Canon, the 5D is a much better buy, has great high ISO capabilities, can get one for anywhere from $1200-1600 depending on research
2- wait for Canon to finally catch up with the Nikon D700, at least. And if you need interesting new cameras (other than Nikon's D700), look at the Olympus E-P1 and the Panasonic G1 .. or even the Sigma DP2.
Or spend on great new lenses (I assume you already have a Canon EOS, if not I don't understand why you'd want to start with Canon .. I do have mostly Canon gear and would switch in a heartbeat to a Nikon D700 if it weren't for my current Canon lenses and peripherals). If you do want to stick with Canon, then even an Xti and a couple great lenses would be a smarter decision in the long run. The XTi or even XSi are remarkable cams for their prices.
Just saying. If you look at my stream
http://www.flickr.com/photos/nycandre/ you'll note that I only add the camera information. That's because I use a few different cams and to me it's only the end result, the photo, that counts. Some of my best shots were taken with.. a Fuji F10. Though of course most are shot with the best cam I can use.
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NYCandre -
http://www.flickr.com/photos/nycandre/ 
