I would let campbell go, dont know about bramble? http://www.mirror.co.uk/sport/football/transfer-news/sunderland-set-to-offload-titus-bramble-1487001
As we have seen this season we do not have a strong enough squad Bramble and Campbell are not regulars and are out of contract at the end of the season we need 7 or 8 new faces in the next 2 windows and players need to go to make room on the wage bill makes sense to me to let these go in Jan and try and get a small transfer fee for both rather than letting them go for nothing at the end of the season
Bramble is our best centre back imo and if he's on silly wages we should negotiate a fair wage. I cantt see us getting a massive fee for him in January and we'd probably end up strengthening a team we are competing with e.g Saints, Reading, QPR, Norwich