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.
I was the one who would port it to Bukkit. Just notify me (or sending an email might even be better) if you have something I can port. I could also attempt to hack together my own version from the decompiled sources, but I'd rather port something official.