Lavdumper - up until now not a single pilot has left for easyJet or Ryanair. If this rumour is true then it is the first time it has happened. GB has 4 more Airbuses (All A320s I believe) coming next year to replace 737s.
It is a great company to work for, and at least one pilot I know turned down easyJet to fly Airbuses at GB. If people want to leave then it's one more step up the seniority ladder for everyone else, so there will be no complaints from the boys and girls on the shop floor.