I go with the view that the bubble itself will not burst but the players will change.
Low Cost as a concept is here to stay, no doubt about that. The expansion potential in western Europe is very high. One of the main limiting factors at present is the way ATC is run by the politicians.
However, the LCCs will merge, take each other over and some will want to become 'big boys' and play with the big toys. We have no longstanding example of long haul LCC. South West operates within a single country and that simplifies their admin 100%.
GO is gone and others will follow, that is the way commerce operates - whether it is supermarkets or airlines!