When chatting to the nice ladies in the terraces lounge at txl last month they said the lounge in BER will be a oneworld lounge managed by airberlin. They did mention that BA had at one point even contemplated reversing their decision not to have a BA Galleries at the new airport but by that time it was too late to make any changes.

Who knows, perhaps they may decide on having a dedicated BA lounge at a future date after all...