Did some digging today and it looks like Blizzard are updating a few of the old weapons with new skins. Only a few are available, I expect to see some Alliance ones/the rest of the Horde ones in there by next patch. This is what is available thus far:
No idea where they're from, but thought it was worth a show. Didn't Ghostcrawler say that there'd be some fancy new PvP rewards or the like a few weeks back?