[X-HW] Canon or Nikon cameras and OS X

[John]

I haven't done the cursory google search yet, but I was wondering if 
anyone had any experience with either the Nikon D70 OR Canon EOD-20D, 
and OS X. I'm specifically interested in using the camera control 
software (does Nikon charge extra for it?), and getting a preview on my 
computer (Ti PB G4).

Note the preview on the computer requirement - I have a Nikon 995 at 
the moment, but would like to move up to something a bit more advanced, 
with the ability of computer control+preview AND an interchangeable 
lens. I do understand that both cameras have USB 2.0, and my laptop 
does not (as of now...). I could technically move to an earlier 
generation Canon or Nikon*, but generally have avoided that in my 
technology purchases. I believe the Nikon has been out for a while now, 
and could be due for a refresh "soon".

Thanks!