Most of the book will be taken up with catching Mat and Perrin's timelines up to where Rand and Egwene are now.

As far as the pure military situation on the ground, there have been hints (both in the books and in comments from RJ and BS) that the shadow forces coming out of the blight will have overwhelming numbers, and they'll likely be concentrated much better than the currently scattered forces of the Light. As for channelers, while the Light clearly has greater numbers, only the Asha'man among them are truly prepared for the type of war that's coming, and to counter that, it's very likely that Taim's disciples have been better trained.

If something doesn't happen to bring the Seanchan over to the side of the light, things look very bleak indeed.