I would assume whatever remains of Umbrella and/or Tricell. Capcom makes no plans on using old characters. Rebecca, Barry, Sherry, and Steve will not appear any time soon, especially in the same game. Everyone thought Steve and Sherry would appear in RE5, but, Capcom has no intentions on using them. You will only see Steve in the same game as Claire as Leon in the same game as Ada. Sherry was basically replaced in 4 by Ashley. There's no word on a new game anyways.