When I heard the title of the next book was going to be "Towers of Midnight" my first thought was that we would be seeing a lot of what's going on at the Black Tower, as well as finally getting to see Moiraine's rescue scene(s) at the Tower of Ghenji. I don't think there's any reason for the Seanchan to go back to their homeland just yet, since they're still consolidating their hold on Randland.

I'm assuming that the last book is going to be focused almost entirely on the Final Battle. There are going to be so many disparate elements, so many different battles and enemies to be overcome, that I think that the entire book, or at least a good 90% of it, will be devoted entirely to the siege of Shayol Ghul. That means Sanderson is going to have to wrap up most of the other major storylines in this next book.

Looking at TGS and the parallels between what's going on with Rand and the events at the Tower, there's going to be a similar layout in the next book: two major storylines with a couple of chapters on the sidelines to wrap up some of the minor bits and pieces. TGS focused almost entirely on the White Tower, and Rand's internal struggles. It makes sense for ToM to focus on the troubles in the Black Tower, so we'll probably be seeing the events unfold from Logain's eyes, or someone else not infected by Taim's group. And since the storyline with Mat was just a teaser (what was it, a whole two or three chapters in the entire book?) it also makes sense that this next book will focus a lot more on Mat, and how he rescues Moiraine along with Thom and Noal. (minor theory, not sure if anyone has submitted this: Noal dies, and Olver becomes the third person to tag along. His superior knowledge of Snakes and Foxes allows them to be beaten and they all escape.)

Also, Harriet mentioned at JordanCon that if there were followup books to WoT, it would focus on the return to Seanchan. With that bit of info, I'm pretty confident that events are going to stay on this side of the ocean.

I don't think we'll see a lot of Rand or Egwene in ToM if only because there was so much of them in this book, and because there's such a time lapse in what we see from Perrin's viewpoint, and what we see from Rand's. with that time disparity, Sanderson will have to focus on the characters he neglected, if only to bring everyone together in time to kick the Shadow's butt.

Thus, Tavi's theory (if a woefully uneducated one) is that ToM doesn't refer to the Seanchan landmark of the same name. It's an allusion to the darkness brewing inside the major Tower landmarks on the main continent. Don't beat it up too much.