Chris,
I read a lot of reviews on the net, watched Andrew Birkbeck snap great photos @ recent AMPS (with Nikon D50) and attended a seminar at that show on digital model photography. As a result, I recently got Nikon D40 and I absolutely love it! I got the simplest set (with 1 kit lens - 18-55, no VR), but so far I have to say that the camera is better than the operator

.
One thing that made biggest difference for me is a decent "setup" to take pictures. IMHO I'd say that this setup might even be more important than the type/kind of the camera itself. Here are few pictures to give you an idea of what I'm talking about:
http://picasaweb.google.com/szczesnyb/PhotoSetupSeanSki
http://www.pme.org.pl
--
"Car's grip is greatly reduced when wheels are not touching the ground" - Steve Matchett