The company is extremely stable long term. It seems like a great place to settle down. Also, Microsoft is so big, you'll find someone doing just about everything in software development. Movement is easy, if you look for it, and you get to work with a lot of great people
Cons
The company is sometimes a bit too big. You can see how the cogs turn a bit slowly at times. This also means the company has accumulated a lot through the years, which makes fixing issues extremely hard at times.