Pros
I am excited to be at AT&T. The company has undergone a period of extraordinary preparation for the next phase of its evolution. The merger with SBC and the acquisitions of Bellsouth and Cingular provide the scale necessary for innovation. Innovation is well underway in wireless with the iPhone and IP based TV via the Uverse offering. Both are spectacular. On the enterprise side AT&T has moved significantly away from a provider of "dumb pipes" by adding some exceptional ntelligence inside the global network. From a career standpoint, It is advantageous to be at a company that is re-inventing itself as profoundly and confidently as AT&T. Watch AT&T closely over the next several years and you might be amazed. I find very talented people wanting to come to AT&T, a position they would not have considered just a few years ago.
Cons
Few companies have re-invented themselves at the macro level this fast, so some things are not perfect . . . . yet. Some might argue that internal politics still plays a dominant role. I view that, not as internal politics, but as strong executive relationships. Any company of this size has many systems that need to work together better. However, I have seen the company react positively and nimbally in this area.