I think the fundamental issue here is the differentiation between "discretionary travel" i.e.leisure and non discretionary business / commuter travel. Locos for the most part concentrate on leisure discretionary routes (FR, EZY - although EZY less so) and its these that will obviously be hit.
The likes of FR won't and don't capitalise upon business travellers and routes. Take Paris as an example - FR keep costs down by flying into lower usage regional hubs (Beauvais) which have zero use for business travelling pax. As the credit crunch worsens, people aren't going to want to fly to regional European airports as these really only serve the leisure market and of course as consumers tighten the purse strings leisure traffic will hit an all time low.
You can hedge your fuel and costs until the cows come home, but that has b***er all significance if your route structure doesn't create the required yields.