Considering the items I discussed in the topic Version 1.4 for the Holidays? , I think version 1.4 will piggyback quickly to version 1.3 just before the holidays.
With a lot of the game mechanical updates done and bugs fixed for the time being, it seems to be lining up well for HG to take advantage of the renewed attention to the game just before the shopping season. In this theory, I suspect that version 1.4 will be mainly a story and lore update that follows the resumption of the ARG with Altas V4s.
I think (/my hope is) that the presentation of a villain to the universe, especially with a Lovecraftian flavor, would definitely keep the interest going.