Pros
The benefits package cannot be beat. If you are risk-averse but still talented, it's a perfect opportunity for you. If you have an iota of entrepreneurial spirit, go elsewhere.
Cons
Many, if not most people you work with and meet have only ever worked at one company: MICROSOFT. They believe that the Microsoft way is the ONLY way. They don't care to hear alternatives. Your mileage varies depending on who you report to: If you're reporting to someone solid, you can have a great experience and be positive that Microsoft is a FANTASTIC place, be promoted every 18 months, and think anyone who speaks negatively about Microsoft is nuts. If you're working for a poor manager, you'll encounter cronyism, politics, promotions that have no correlation to merit, and difficulty figuring out where your future at the company is, if any. Be prepared to be assigned to projects that don't make a lot of sense, but are pets to high-ranking execs.
