This is definitely a nice way of doing it. I don't know if it really fits in with your idea, but I figure it'd be nice to extend this to all armour and kill two birds with one rune, as a number of people (myself included) would like to be able to continue to have the appearance of the starting armour later in the game.
I suppose that I don't really see any reason why this could not apply to all equipment and not just uniques.
