A new character will be revealed for Metal Gear Rising: Revengeance at this year's Tokyo Game Show, set to take place late next month. Siliconera says that both Raiden and this new mystery character will be revealed at the show. Any guesses, Destructoid? We'll be there to confirm for you.
Konami says that they're recording voiceovers for the game now. Fun notes: Final Fantasy XII's Balthier, Hiroaki Hirata, plays a role (Sam). Kenyuu Horiuchi is Raiden again in the Japanese version, and he was Angel in Buffy the Vampire Slayer in Japan.