I don't think I've ever seen this brought up before, but I could be totally wrong. It'd be nice if there was some way to replace the current playlist, but only after finishing the current song, or, maybe, the current playlist. For the latter, I realize that I could just append, but then I've got a playlist that contains both original playlists, so I can't just restart the latter playlist, plus the playlist [xx/yy] numbers no longer correspond to track numbers for playlists which are albums (which could be ignored if track number display were implemented).