Sorry for the "y'all." I'm listening to pedal steel guitar music, and it's bringing out my time spent in the South.

Anyway, Liam Neeson, who played villain Ra's al-Ghul in Batman Begins, has confirmed that he was, in fact, on set for The Dark Knight Rises, something that's been in the rumor mill for almost a year now. He didn't confirm that he shot anything, but it stands to a decent amount of reason that if he was on set, he most likely shot a brief cameo. Consider the all-but-confirmed fact that Marion Cotillard is actually playing Talia al-Ghul, daughter of Ra's, and that young actress Joey King confirmed she was playing a young Talia, and you've got the very real possibility of Ra's showing up in a flashback to fill in Talia's backstory in the "surprise" reveal that she's related to Ra's. 

Max and I have discussed the possibility of Ra's showing up again via a Lazarus Pit, the method Ra's used in the comics to extend his life across hundreds of years, heal injuries, and go quite mad. I think that level of supernatural stuff is completely out of line with Nolan's Bativerse, but it's certainly a possibility, considering the character's history.