m&n,
It is not yet confirmed what changes, if any, Easy will make to the flights currently operated by GB once they are subsumed in to the orange empire. Easy have said that they will offer refunds to those who have booked before the sale is confirmed if passengers do not wish to take a flight with Easy. The contract will only be broken if explicit terms of that contract are not fulfilled. For example, if your ticket includes meals (all LGW and LHR flights include appropriate meals) and a given hold baggage allowance and these are not provided, then there is a breach of contract. If the boarding arrangements change to non-allocated seating or the seat pitch changes, then these changes alone will not constitute a breach of contract as they are not explicit terms therein.
Therefore, as I see it, Easy are pre-empting the need to battle for a refund by freely stating that they will be offering it, even before they have confirmed the changes they intend to make to the service currently offered.
If you have any solid information as to the changes Easy are going to make to the service after March 29th 2008, then please feel free to share them here as it will help people decide whether to cancel their booking when the sale is confirmed or even to reassure people who are considering making a booking for a flight after that date.
Cheers,
Jet