Pros
Company is very accepting of individuality - generally, you can wear what you like and be yourself without any negativity. As I worked my way up the ladder a bit, the work got somewhat interesting, but was very repetitive at first as a regular GM.
Cons
It's like high school. There are cliques all around, and if you aren't in the right ones, be prepared to not get very far up the chain. Everyone works, lives, and socializes together, and HUGE importance is put on the "Blizzard Family." You will be required to work odd hours, holidays, and countless overtime. Do NOT expect to have a life outside of your "Blizzard Family." If you try, you will be essentially excommunicated and out of a job soon. There is NO work-life balance when working for Blizzard, because Blizzard expects their employees to be devoted gamers who have no life other than Blizzard.