I think it would be a great idea, but the layered versioning is a little too complex. How about each reply gets assigned a number, and you can link back to it with [310461|something like this]. You could even have some kind of pseudo-protocol that would make the server look up the reply title and use that as the link, maybe like [id://310461]. What do you all think? Sounds a little difficult, but I think we could all get used to it in time.