Yep! Eventually, WriteFreely will have all of these different “apps” built directly into it. Some discussion on that here:
As for a definite timeline, I don’t have one today, unfortunately. You can check out our roadmap, but right now my biggest focus is collaborative blogging on Write.as. Of course, the more interest we see in making Snap.as open source, the more we might be able to prioritize that. But there is also plenty of product development to do before that can happen, I think.
Is there a particular reason you’re interested in a self-hosted version? E.g. do you need photo hosting for your WriteFreely instance?