I have been shooting with a Canon 5D and recently tried a Nikon D3. While I thought the technicalities of the Nikon were superb, there was a slightly different color palate present.
Do you find the two cameras... shooting RAW... converted by same ACR in CS3... give a somewhat different "color look"?
I think the default colour renderings differ between my Canon 5D and 1Ds3 in DPP at least. I've not done any close comparison in ACR yet, and the 5D is calibrated already so the rendering is no longer ACR standard, but yes renderings from different cameras can look different. DXo allows you to render files from one camera to look like the default from another...