Pros
Big international company with lots of advancement opportunities. Good place for talented young journalists to gain experience and broaden horizons, and for those further along in their career to learn new skills. Some truly excellent, smart, decent human beings here, and you'll never want for challenges. Compensation and benefits are good by industry standards, especially after you've been here a while. AP is relatively well positioned to deal with the tectonic shifts affecting the news business, with some core technology pieces (e.g. centralized content database and tagging system) now in place to build on.
Cons
AP's corporate structure is unchanged since its founding in the mid-19th Century: a not-for-profit cooperative, owned by its newspaper members. As such, AP acutely feels the financial woes of its members, and that has resulted in a staff reduction -- so far mainly through early retirement, but with a round of layoffs seemingly inevitable at this writing -- that has cost the company many valuable employees already. It remains to be seen whether this brings costs in line with revenues without undermining AP journalism, or if it's the start of a death spiral as appears to be the case at so many of the member newspapers. As it struggles to cope with the communications revolution, AP sometimes launches new initiatives to great fanfare, only to have them die quietly on the vine under member pressure/market reality, to be replaced by the latest and greatest shiny new object. The empirical basis for major business decisions is not always apparent, despite lip service paid to "transparency."