As much as its fun to see new versions of the "big name" characters, I'd love to see more of a focus on historical figures and the famous heroes and villains of the books. Such as:
Dunk and Egg...
Bloodraven (perferably two verions, both as the King's Hand and as a member of the Nights Watch)
Bittersteel (or any of ther heroes from when the Red Dragons fought the Black Dragons)
The Smiling Knight (or any of the historical outlaws)
The White Bull (or any of the historical Kingsguard)
If we had enough historical figures it would allow for more variety in deckbuilding, especially for the Targaryens as they have so many interesting members of their family... who are almost all dead.
Judd