The next Batman movie hasn't even been written yet. We don't know what villains will be in it or what the story would be about. What about seeing the return of Ra's al Ghul? He is a formidable Bat-villain. Josh Horowitz from MTV ran into Liam Neeson at Sundance and asked him about it.
I have to say I wouldn't mind seeing him return. Maybe not as the primary villain but in some capacity. He's too good of a villain to let just go away. Guess we'll have to wait and see.