As noted in this thread, I’ve been waiting to see more of Esk ever since the first Discworld novel I ever read, Equal Rites. Now Pratchett is hinting – only hinting, mind you – that she might reappear in the next Tiffany Aching novel, I Shall Wear Midnight. 
Cool beans. I saw him at a book signing once in Berkeley, and he was asked if he was ever going to write more about Esk. He said that he’d always planned to, he’d just never found a story that needed her. And he couldn’t justify forcing it when other stories kept coming.
Yay - I always thought Equal Rites was a better book than it seems most everyone else did, and I loved Eskarina. Tiffany seemed to me a more fleshed-out version of Esk.
Oh, goody. Esk was a great character.