I've been doing a lot of thinking about what the next deluxe expansion and AP series will be about and I've come to the following conclusion:
Deluxe Expansion = Rohan, probably centered around the ascent of Grima Wormtongue and Theoden's slip into delusion.
Adventure Packs = Boromir's journey from Gondor to Rivendell.
Here's my rationale. We know that the timeline will be between the Hobbit and the LotR books. Looking at the big stories that Tolkien wrote for this time period, most of them have already been covered (golum's story, the failed return to Moria by the dwarves, the troubles in Gondor). What's left? Tolkien specifically wrote about the corruption of Saruman, the assault on Dol Guldur, the troubles in Rohan, Boromir's journey north, and the ride of Ring Wraiths north to Hobbiton. I think Saruman's tale doesn't really lend itself to the kinds of adventures we've seen so far and I really doubt we'll go back to Dol Guldur so soon after the Mirkwood cycle.
Of the stories that are left, I think Rohan lends itself nicely to a three quest deluxe expansion, and more importantly, it easily provides the encounter sets to enable Boromir's journey north to be the next AP cycle. Why do I think Boromir's tale will be next? First of all, it's a truly epic journey. Boromir travelled west from Gondor, through Rohan and the Gap and then through the wildlands and north to the ruins of Tharbad where he lost his horse trying to cross the great river Greyflood. After losing his horse he had to go the rest of the way to Rivendell on foot. This would make an amazing story, something Tolkien said himself : "the courage and hardihood required is not fully recognized in the narrative". That's the kind of journey I'd like to see in an AP cycle. Tolkien's lack of detail about the journey is actually a blessing to the game designers as they can have some fun filling in the details of the story. The regions around Tharbad were also not in the movies giving the designers some freedom to conceptualize them however they want. The fact that a third of the trip is through Rohan would dovetail very nicely with the Deluxe Expansion.
So there's my prediction. What do you think?