The mentality of workers entering corporate jobs has changed significantly over the past thirty years. Jobs that were once seen as cradle-to-grave positions are increasingly rare. New employees must learn to accept that their jobs are likely to be more short-term than in the past. There is no simple answer to what the new social contract is for employees, though it likely has to do with rewarding productivity instead of loyalty.
See "A New Game at the Office: Many Young Workers Accept Fewer Guarantees", Steve Lohr, The New York Times, December 4, 2005