Some interesting posts. Some weird and wonderful arguments, that is what makes flying interesting. Rather than concentrating on what people actually fly with we could concentrate on what is the legal minimum. And then just project ahead that someday that may be what everybody has in the BNN/OCK/LAM/BIG hold. Fuel is a very personal thing, I would suggest that the fact that there aren't multiple MAYDAY and diversions everyday would suggest that those professionals in the pointy end know what they are doing. So not talking about what you should carry but what you may carry.
Assuming all contingency has been used up (and we don't even have the good old 15mins any more at BA but that's another storey)
Within 2hrs of destination providing the destination has 2 RW's we can commit. We no longer need diversion fuel. Provided in the opinion of the Capt a safe landing is assured. Once we receive an EAT the requirement for 2 RW's no longer exists. We can plan to arrive with just reserve fuel. (As most EAT's involve holding this means in practise that you can go round the hold till you have Reserve plus what you anticipate for the approach.)
So the significance of an EAT is that is changes the parameters by which the flight crew make their decision. As such it should never be moved backwards.
Gonzo made a really interesting point about landing on Easterlies. Can you regard this as a twin RW operation? I have my doubts due to the length of time it takes to get 09R up and running. However calling it a single RW operation would mean that until we receive an EAT we couldn't dispense with diversion fuel.