So I was thinking about this for a while over the last week or two and realised that the Secrets of Oldtown cycle will end in August and Dance with Dragons is scheduled to be released in September (here's to hoping o.O) but the way that chapter pack cycle development goes its very likely that cycle 7 is already partially in development and therefore Dance wont be finished in time to provide fresh material for it. I know its a little early to be thinking about it, seeing as Secrets of Oldtown hasnt even gone on sale yet but the fact that the source material is geting more and more used up made speculation really intriguing for me!
I think that one way of keeping the themes and contents of the chapter packs fresh and engaging FFG will need to move beyond the "current timeline" of the stories and really widen the net as it were for what parts of the universe get cardified. Not only is the mythology and history of Westeros and the rest of this world incredibly vast but the more recent tales of heroic battles and personalities such as Balon Greyjoy's Rebellion and the Battle of Redgrass Field are prevalent throughout the series and sometimes even directly invovled in the plot. Therefore I give you:
Times of Legend! Drawing heavily from the rich and colourfull mthology and history of Asoiaf's universe come 6 chapter packs full of influential heros, world changing events and song worthy battles. New mechanics could include a suped up version of Renown or the new trait synergy with a Legendary Hero trait or even a new keyword of the same name? There could even be a "Time of Legends" Agenda encouraging players to make challanges with single, Heroic characters or massive challanges with big Armies! On top of that, any important event or situation in the history or mythology (Long Night, Field of Fire, Redgrass Field etc.) could be used to make events, plots, agendas or even just chapter pack names.
Lannisters: Now Im not entirley sure what they would get, I was never very well versed with their history or mythology, but they Do have several interesting possibilities. Firstly and most recently, the Brave Companions are not in the game so hey, theres a Bolton esque mechanic at work right there! Next we have the obvious possiblity of Lan the Clever being their "Legendary Hero." There is also a great possiblity to bring in The Field of Fire as a Lannister related event or plot and characters/armies that participated there could be used too, including the old kings of the Rock? Lastly the pervasive history of the Reynes and Tarbecks could very easily lend itself to another Botlon esque mechanic!
Starks: The starks have a strong history, with an abunance of Old Gods related mythology and a host of previous kings of the north. Lyanna Stark could make an apperance and so could Brandon? Bran the Builder is an obvious choice of Legendary Hero and House Reed are still absent from the card game and could get much semi-magical love in this sort of cycle. On top of this the Old Gods could also have more represintation and as with all houses the times of Agon the Conqurer could spawn famous kings and events.
Targaryens: The Targs would get the most obvious love from this. With Dragons, lots of Dragon Kings and their strong roots in ancient Valyria their mythology and history is Incredibly easy to adapt for this sort of thing including the possiblity of a whole Theme around the Blackfyre rebelions. Also, can anyone say Meraxes, Vhagar and Silverwing? Moar Dragons! xD
Martells: The Martells are also very good at this. Their historical ties to Nymeria provides a perfect Legendary Hero and their military prowess and history of stealthy warfare make for interesting new mechanics and possible battles. Their locations such as The Boneway would be fantastic for this sort of stuff. Admitedly having only come into the story in the previous book in a big way they might end up a bit lacking in parts but Im sure enough scaning of the books would produce enough epic history to satisfy any Martell player.
Baratheons: The Lords of the Storm. Nuf said. The Storm Kings are Great history, all of them. On top of this the Baratheons have always had the most epic knights, this could help them out with their already preffered Knight agenda. Theyre one of the First great houses and therefore full of history. Orys Baratheon is a great Legendary Hero, one of Agons best generals, and charcters like Argilac the Arogant are full of possiblity!
Greyjoy: These would probably get the most love next to the Targs. Between Harren The Black, their tendency to stick to old tradition and Balon's Rebellion theyre basically Legend-fodder. Harren or The Grey King would make fantastic Legendary Heros while The Burning of Harrenhall would make for a great event or plot. On top of that "Return to the Old Ways" could be a Reaver and/or Drowned God boosting agenda!
Neutrals: As in the last three chapter pack cycles netural characters would get a lot of atention too. Legends such as Floarian and Jonquil, The Dragonknight and The Knight of the Laughing Tree would all end up being fantastic characters, who knows, maybe even Azor Ahai himself could get a card? Old Kingsguard such as Duncan the Tall could link the short stories to the LCG and boost the existing Kingsguard agenda. The Others could get more atention, recieving some characters or plots, maybe even The Long Night as an event or plot! In direct opposition the Night's Watch has Fantastic history and mythology such as Bloodraven and The Black King. The Kingswood Brotherhood would mesh well with the Brootherhood agenda and the abundance of Epic Batlles such as Redgrass Field would definatley boost the Epic Battles mechanic and the Military Battle plot mechanic!
Really there is a Lot of potential in a chapter pack cycle like this that draws from as of yet mostly untapped areas of the books and overall story. It would be Fascinating to see all the mechanics and artwork that would evolve from these themes and at the end of the day, no one can argue with more dragons! What do You think?