Here's a question for you guys: How sympathetic do you think Bane should be?
With BB we got Ras Al Ghul. A fairly understandable extremist, not someone you cried for when he went off the rails but still someone you couldn't help but understand where he's coming from (I'm a big fan of Neeson's Ras, doesn't get enough love. The speeches in BB weren't terribly well-written at times but his were always excellent.)
With TDK we of course got the Joker, who was an almost inhuman force of nature and chaos. I'd argue he comes off as a human whose trying to make himself into that force of nature and chaos, I'm not sure that was what the writers were going for.
I'd like to see Bane be, loath as I am to quote TV Tropes (for those of you who don't know, a strange internet Ceti-Eel that enters your brain and devours your vocabulary), an Anti-Villain. Similar to Ras, someone who does very bad things but you understand his motives, and on some level feel for his plight. I imagine Bane as, like Bruce, a construct of the man behind the mask, though unlike Bruce Bane strives to utterly annhilate whatever person he is underneath it and fully become that mask and persona. So beneath the godlike, emotionless warrior he's still an angry, bitter human being.
For that kind of antagonist to work. Especially if they're going to be doing awful things to characters you care about. Has to be very well-written, admittedly, but I'm sure the Nolan brothers are good enough writers to pull it off without it slipping into Sandman territory where it feels like a forced attempt at wringing sympathy from the audience.