It's been a while, I know, but progress is being made. In fact, I've now finished reading through and annotating The Devil's Gate, and I've now made a start on actually carrying out the edits. I've got the many changes I identified myself from reading the last draft, as well as those suggestions that the others who have read it made, so it might take a while. Having just read it I can safely say the final chapter is if anything even more epic than The Two Empires' one.
Also worth mentioning: if you've got any feedback about The Two Empires you've been keeping to yourself, now's the time to share it! I'd love to know what sort of things you liked or didn't like so that the sequel can hopefully have more or the former than the latter.
I would have posted more in recent weeks, but a) the editing process isn't particularly thrilling to comment on and b) life has been a bit crazy lately. But don't worry: The Devil's Gate is on its way, and I think you're going to really like it.