I don't need it at all, but it seems like a good idea.
It would probably be quite annoying for a selection of short music files, but more useful for longer files that are similar to each other; like "episode 1", "episode 2", etc. or "late night live 2011 May 30 .mp3", "late night live 2011 May 31 .mp3", "late night live 2011 June 01 .mp3".
It could be useful when clicking through tracks with the left and right buttons too. Would that be a different case, or an extension of the above?