The Hound's fate is untold- I imagine purposfully. I imagine he has quite a role to still play- he's a kickass guy... in a semi-evil kinda way.
Arya's list is mostly taken care of... Tickler, Poliver, The Mountain, (The Hound I imagine she no longer wants dead), Joffery, Amoury Lorch, etc.
I allmost want the Mountain to be alive, so the Hound can kill him.
And I want to see Jamie Lanister decide that a certain "maid of Tarth" is a better companion.
Could happen.