Actually, JKR has as good as said we'll see more of Aberforth in Book 7 -- or at least she's spoken in such a way that the only Order member she could be talking about is Aberforth. I wouldn't be surprised if he plays a role similar to the one he plays in this fic... Snape's intel from his spying in Voldy's camp has to go somewhere.

I'm really glad you enjoyed the story so much!