In reply to Timothy Jacobs.

Plug in authors will do it when it's more reasonable to do so and more efficient. One of the great (and sad) things about Wordpress is the relentless push forward. There are no real safe versions or safe stopping points, just a relentless move forward. The vast majority of active wordpress sites are on new versions, unless trapped by software restrictions.

REST will come into it's own over time if it proves to be a better way to program, a better way to develop, and stable enough for both. For the moment, it's none of those things, and certainly doesn't belong in core - YET.