Pros
From the perspective of anyone who joined in the last 3-4 years, Pfizer is a very employee friendly company from the perspective of salary and benefits and the people are generally nice. If you want an opportunity to have an impact at a big pharmaco, now's the time at Pfizer. The company is forced to accept new ideas and forced to accept change at a rate that it would otherwise resist. So if you want good experience managing change in a Fortune 100, this is a good time to be at Pfizer.
Cons
Employees have been at Pfizer for many years that they cannot help but be discouraged now that the good times are clearly over. There is massive optimization required for survival. This means systems, processes and organizations need to be redesigned, reshaped and shrunk from top to bottom. Additionally, bonuses are no longer going to be guaranteed the way they essentially were in the past, raises are going to be smaller, etc. So it's a tough time to be at Pfizer in that our colleague's proverbial cheese hasn't just been just moved, it's been (and will continue to be) completely VAPORIZED. Don't look here (or stay here) if you're want predictability and stability. It's going to be a pressure cooker until November 2011.