Pros
The pay is good, depending on what business unit you're in. They have a fairly good view of work/life balance and are respectful of people's life away from work. The people are decent and management is fairly good. It would be better if upper management did communicate better to the rest of us what they are doing instead of giving commands to us just to execute.
Cons
There is some tension between the businesses and headquarters. Sometimes, we get objectives that are very high, maybe unreasonable, to some. There is no real culture at AT*T. It really varies by what region/business unit you're in. They are buying out companies left and right and sometimes they really don't think through how they are going to strategically integrate everything together into one unified front.