I'm not as doomsday as Rosbif on this one. I don't think Transat is in Danger of competition from AC, they have there own niche and they serve it well.
I also can say you will never see a merge with AT and Westjet, they have totally diffrent views on running an airline, and Westjet's culture makes mergers almost impossible.
What I do think is AT itself wants to get out of the airline business. The ols saying is true if you have 2 million dollars and you want to be a millionaire, start and airline. Basically you'll loose your shirt.
I think Transat has done very well and still does well but the evolution of the company seems to point to a focus on selling the packages only. Whatever happens someone will be flying, wether it be Transat or another so I think the jobs point is moot, they will be around in one form or another.
Good luck to all