Pros
Enormous resources, _normally_ a place to pursue a stable career (except in this economy), you can make an important difference in peoples' lives, the work is challenging, the coworkers are smart and constructive (if rather bland), the technical management is generally quite good (far better than the non-technical hierarchy).
Cons
Very bureaucratic, hierarchical, top heavy, often uncreative, lacking imagination, too reluctant to take risks, FAR too much willingness to stick with tradition (old school/old boy). Strongly moving toward outsourcing (even of research). Already outsourcing over 80% of its IT. Way too much group-think among uppermost management. Upper management is incredibly oversensitive to legal threats of all kinds, even anticipating potential threats from employees themselves.