Anne Hathaway has also been confirmed to be on the casting, so it's unclear what kind of role either of them would play. Hathaway so far has been rumoured to be taking on the role of anti-hero and potential Wayne love interest Catwoman. It's likely that Nolan will want to minimise the introduction of too many new character threads, and so currently the buzz around is that of family links for the new characters back to the previous films of the trilogy. It's been rumoured that Gordon-Levitt will play Alberto Falcone, the son of mob boss Carmine Falcone who figured heavily in Batman Begins. It might follow then that Cotillard will play Talia Al Ghul, the daughter of Begins villain Ra's Al Ghul (Liam Neeson). In the comics, Talia and Batman have an on-off relationship and a child together. With the death of Rachel Dawes in The Dark Knight, a love triangle between Batman, Catwoman and Talia could be an interesting plot point.
Of course the Batman rumour trail has taken many twists already and it would be surprising if it didn't throw up anymore new developments before it starts production over the summer. What is for sure is this is going to be an epic-length picture and with Nolan at the helm, it'll have plenty of interesting and intertwining character arcs. As a huge fan of what Nolan's done to the franchise so far, I'm looking forward to seeing where he's going with the final chapter (?) in the story.
