Facebook recently rolled out the ability to edit comments on posting, which naturally led to an obvious question: what about editing the posts themselves? A product manager for the company, Vadim Lavrusik, spoke at a journalism conference and reportedly hinted that it would be coming soon. In the context of speaking about comment editing, he said, "You can infer what we will do next." As Wired points out, Lavrusik declined to confirm definitively that the feature was coming, but told the LA Times that "Often, Facebook sees things its users are trying to do and responds by making features that let users do those things more easily."
If Facebook does implement the oft-requested feature, it seems probable that it wouuld use some of the same features that it added for comment editing. Namely, a full history of the original post along with the final, edited version. That would help prevent a user from posting one thing and then changing it later in order to trick commenters — who could look at the full editing history of the post.