I looked through the back few pages, and maybe I'm blind, but I couldn't see a thread dedicated to this topic, despite the fact that everyone's talking about it anyway...
I heard a couple of things, firstly that Space Wolf Lost companies are on thier way, from the eye of Terror, lost amidst their great hunts, and they aren't especially pro imperial anymore. I doubt that however.
I also Heard that They're re-releasing Ulthwe. That sounds copmpletely bizarre to me. Could they actually bring out the Harlequins? (possible, considering Arhimen's recent discovery of the entrance to the Black Library, and jabberings about the conclave of Har, with Inquisitor Czevak)
Most know that Cadians are on their way, along with, most likely, a list for Chaos cultists, i.e. non Space Marines Chaos worshippers.
Add to this a very large number of hints about Abbadon's 13th black crusade, including his knowledge of the Dragon in addition to the recent Necron Codex, the Gothic war's capture of 2/3 of the Talismens of Vaul, who were used specifically to defeat the Necrons, and an interesting storyline picture emerges.
I know that some have already being formulating their prophecies, someone talking about the Eldar retaking the Eye of Terror - not likely by my understanding of the Dire current situation of the Eldar - someting interesting is going to happen in regards to Necrons, Chaos, the Adeptus Mechanicus and the Imperium: Arhimen and his gang throwing the Eldar into the fray as well. The other races will likely be the unknowing (or uncaring in the Case of the Nids) tools of the devious fate weavers - Ulthwe, Tzeentch and the Deceiver.