Currently, the only thing we know for sure about this game, is that it will not be the same game as Resident Evil 5 for the Playstation 3 and Xbox 360, but the Resident Evil fan site Rehorror.net recently interviewed the voice actor Tara Platt, who will voice Jill Valentine. She said that the game will include Zombie creatures and a great variety of weapons. Since she knew this, she might be one of the main characters in the game.
In addition to that, Gamespot comments have posted up some unconfirmed information that is supposed to be from a gaming magazine in Hong Kong.
"Biohazard : Umbrella Corp Chronicles and fills in the story on Umbrella before and leading to BH4. Gameplay is a mix between using the Wiimote as a light gun and BH4 style elements e.g. action buttons pressing X for a dramatic scene.
It features scenarios from BH1 (museum), BH2 (police station), BH3 (raccoon city), BHCV and BH4 (village) and ties in the gaps especially BHCV and BH4. Characters include Chris/Claire, Leon/Ada, Jill / Carlos, Rebecca, Hunk and Wesker. There are two gameplay modes - scenario mode and arcade mode. Proper announcement to be made by Capcom at TGS"