WB has stated that Roger Craig Smith
will be voicing Batman, and Troy Baker
(Robin in AC) will be voicing Joker.
This is interesting given Conroy explicitly stating that he had been working on "the next Arkham" for about 10 months. Hmm...
And here's the full trailer for AO:
Other villains confirmed to appear in the game are Anarky, who appears to be filling the "Riddler" role from previous games, and Bane (not pictured) who is said to be "more like the comics."
In addition WB Games Montreal revealed a new gameplay mechanic that allows players to recreate crimes at the scene with the ability to pause, fast-forward, and rewind. Another new detail is that while "Origins" takes place several years before the previous Arkham games, there's a five year span between "Arkham Asylum" and "Arkham City," leaving plenty of potential room to explore in the future.
Click link for images.