From Sam on the old bugtracker:

Being able to track changes to guides and fixes would be useful for personal guides or fixes. I think it will be absolutely essential for team fixes and guides so that one member cannot accidentally (or purposefully, or drunkenly) destroy a team guide. So if Angus decides to come out and spew some drunken nonsense in place of a perfect guide that took days of work, it can all get fixed in the morning.