Clint- check out page 260/261. They talk about domains briefly, and give an example of a log object (the cut ends have a wood grain shader applied to them; the outside of the log has a bark shader). I haven't tried this yet, so I can't attest to how it works, but my understanding of shader domains is that you have to make your shader a layer list shader and assign a mapping mode to enable them. Thus if your top component is "Multi Channel," domains will not be enabled. Try making your top channel "Layer List," then add "Parametric" below that, then "Multi Channel." Theoretically, this will give you domains to choose from. Check out the manual (page 305) for more info. I've been meaning to play around with this, actually- it's a great idea. Automatically splitting objects into logical shading domains could be a huge time-saver.