One subtlety that many may have missed is this: Ba had planned their contingency ops using many volunteer cabin crew. In many cases these are being stood down as real cabin crew turn up and man the flights. This was true yesterday, if it continues in this vein there will be less disruption in the gap between strikes as so many pilots and engineers etc will not be away down route but will be in the uk ready to continue with their normal jobs.
I suspect that the second set of strikes will be less well supported by union staff, strikers feeling that they have made their point but cannot afford to lose any more money etc.