I just installed the latest version of v5. And when I try to run the RenderedShadows, it shows up very similar to the Rendered viewport.
I'm virtualizing Windows 64bit with Windows 7
Thanks Bob, I am using the OSX version and get the RenderedShadows there, which is very nice. But I can't seem to give up VMWare's ease of use over bootcamp.
Just so you know, you're on your own with respect to virtualization:
From the System Requirements page for Rhino for Windows: