Interesting... I remember thinking those were odd labels when I first installed a second hard drive ten or so years ago.
My opinion is somewhat split... whoever picked the terms was an idiot, now they're so firmly entrenched in engineering standards that it would be a difficult swap out. Just getting the affected communities to decide on new terms would take forever... not to mention master/slave lingo applies to more than one setup, in fact, I've never seen/heard of bluedragon's definition of a master/slave relationship.
To me this would definitely be the kind of thing that would be a "phase out" move it were to ever happen. I mean you're talking documentation, labels, textbooks.
So in short, I think it'd be nice to shrug the labels, but I don't see it happening.. so why don't we just go kick the shins of the grandkids of the guy who came up with it.
-Rob