The SFO-Europe market is on fire right now. The economy has come out of the gates and nobody -- air carriers included -- predicted this.
BA, and the others, will certainly cut the overbooking by selling fewer cheap seats and by raising prices, but that does not happen overnight. Those overbookings leading to oversales are being made largely at walk-up prices. And, that easily justifies paying out significant VDB.
The future does not necessarily portend greater frequencies, but rather higher fares.