Given Christopher Nolan's avowed hatred for including deleted scenes on his DVD releases, this seems unlikely. But the website Nuke the Fridge is claiming that the DVD/Blu-ray release of The Dark Knight Rises will include a "Director's Cut" that's half an hour longer. Including the origins of Bane, plus more screen time for Liam Neeson as Ra's Al-Ghul. Even Nuke the Fridge, whose report is based on unnamed "sources," warn that this should be taken with several grains of salt. But it's getting picked up other places, so just FYI. [Nuke the Fridge]
I would love for this to be true. As much as I enjoyed the movie, even at 2hrs 45min, it felt a little rushed in some spots. So it would be interesting to see if they addressed that with any extended cut (if it actually comes to be). I also would not complain if they added 20-30 minutes of just Anne Hathaway. But that's just me.