Miranda Tate is Talia al Ghul. She is the new head of the League of Shadows. But Bane will not be affiliated with them. He is an entirely different villain, with his own supply of mercs to take over Gotham. The LoS are already planning to overthrow Gotham during the 8 year time lapse and near the middle of the movie Talia and Bane make an agreement to join forces.
-Bane forces Leonid Pavel to build him the Doomsday device we've seen in set photos, and I can confirm that it is a nuclear bomb/EMP machine. After Talia and Bane's agreement, she contacts members of the LoS who are working in the White House (it is implied, possibly as a joke, that the President is in fact a member of the LoS) and other important LoSers to not send in the army or National Guard. They shut off Gotham from the outside world and if anybody tries to get in or out, the bomb will go off.
-The Scarecrow scene description we've read is true, it is the only way to escape Gotham. The criminals are against the LoS and form an unstable and awkward alliance with Batman later in the movie. Scarecrow kidnaps Talia at some point and holds a trial for her (like in the description). Obviously, some mercs come to rescue her and Bane kills Scarecrow.
-The bomb will go off at the end of the movie. This is the shock ending Nolan is planning, Batman tries to save Gotham using the Batwing but it doesn't work. The bomb shuts off all electronics in Gotham as well.
-Now time for some interesting news. There is only one LoS flashback and that was what was filmed with Liam Neeson. Josh Pence doesn't play a young Ras, he plays a Government official. He is basically the guy who deploys Nixon to Gotham and he is the person who realises that the whole Bane/Talia thing is a huge conspiracy. He manages to overthrow the corrupted White House members and begins to evacuate Gotham.
-After everybody's evacuated from Gotham (and the final battle has already happened), Batman and Bane have their final brawl. Catwoman fights with Talia and after they are beaten, Batman offers to take them out of the city. They jump at the chance, beating down Bats and Cats in a suprise attack. They reach the Batwing (called The Bat) and Bane pushes away Talia, taking the vehicle as the only way out of the crumbling city. The bridges are up. Batman and Catwoman have to work with Talia to find a way out of the city. The way they escape is actully brilliant. In Begins, Alfred tells Bruce that his great-grandfather was a part of the underground railroad and that the Batcave came in handy. And that's the answer. The cops of Gotham hide in one of these tunnels when Bane and Talia are ruling Gotham and that's how the team escape.
-The citeizens of Gotham go their seperate ways after immigrating to different cities across America and the world. He didn't go into specifics about this part, but he joked that Wayne Enterprises is re-built in Metropolis.
That's the TDKR spoilers out of the way, now time to delve into the reboot news. WB have only had light discussions about this and are heavily focusing on TDKR. But of course, their minds are flying forward and thinking about the reboot. They really want to reboot it as quick as they can because obviously it's bankable and it needs to rebooted if they want to do a shared universe. They're not looking at actors or directors just yet, but they've kind of figured out a plot of how the movie would go.
-It would be a reboot, but the origin is told in flashbacks. It would show off Batman's detective side, by choosing a heavily-wanted villain for TDKR....
-That's right, The Riddler is the planned villain. Riddler would leave puzzles for Batman to solve and if he got them wrong, someone or something he loved would die. The something refers to a building or something similar *cough Wayne Enterprises cough*.
- Unlike the Nolan trilogy, the movies would be seperate installments. They wouldn't be directly related. So something similar to the connections between BB, TDK and TDKR won't happen.
- It will be more comics-orientated. The series will handle a lot of different genres, including Action, Mystery and Horror. The horror part is about the side villain: Man-Bat. Riddler will kidnap somebody random and prepare to turn them into Man-Bat. If Bats solves the puzzle, he will live. If he gets it wrong, then he'll undergo the operation.
- WB are trying to introduce new villains to the general public, hence Man-Bat. The next part is based on speculation and hints, but the other villains in the franchise will all have either already appeared in a movie (and had their character completely obliverated, like Mr. Freeze) or be completely new (ala Killer Croc, Black Mask and Hugo Strange).
(Who is he? Muhammad? Are horses involved?)