I think Bane is just going to be a big, strong, violent mob boss. I think the inflating muscle Venom drug is going to be gone from the film completely. Apparently even in the comics the character hasn't used the Venom drug in a long while.
http://en.wikipedia.org/wiki/Bane_(comics)
I could maybe see a slight steroids reference dropped in for the fans but not how most media writers make it Bane's main character focus. Every cartoon, movie or game loves making the Venom juice his main "thing" and usually his undoing at the end of the story. Real predictable and cheesy stuff.
It's like Nolan getting rid of the whole lazarus pit stuff from Ra's al Ghul character. He was just a leader of an ancient order of bad guys.
Also, drug use as a defining characteristic of a villain just seems so 80's/90's in nature. Bane's drug angle also smacked of "Just Say No" too much and made him feel like a Captain Planet villain instead of a neurotic Batman villain.
I still think the most important part of Bane character is that he's Batman big, violent, muscley, tough-guy villain. The Batman Heavyweight. Thats his defining characteristic and why I think Nolan picked him for his final Batman tale.
How he works in the mask stuff will be interesting though. That part is hard to make sense of.
Nick