Canon surely has the upper hand when it comes to market share(dont know the breakdown when it comes to d-SLR sales alone).So there should be more Canon shooters rather than Nikoners.
That said, Nikon definitely has better glass(which are also relatively more costly!). A personal observation is that entry level and amateur level bodies are the highest moving segment in D-SLR's and those cameras are more represented by Canon.
Pro photographers have found excellent cameras in the D3 and the D300.