I had a relly great idea.
If it would be possible to make this awesome mod to a Plugin for Bukkit Servers with a API, so that you can record a whole round and after the round you can watch if a player was hacking, or something like that. It would be so nice if that would come because the files of the replays are really small and it wiould be easy to rewatch the round, because you would yust have to download the replay file.
I'll be creating a Sponge plugin (it's nearly finished but still has some nasty bugs which I'll have to get rid of first).
Someone (can't find the thread right now) said that they might port it to Bukkit.
Even though those files seem to be small, depending on the amount of players on your server they might accumulate to a noticeable size.
I don't think it'll be available for 1.7 as there is no ReplayMod for 1.7 and replaying them would require you to create yet another tool/mod.