You can count on finding out who the power players are of each corp, who's up, who's down, what each corp is doing (both public versions and shadow versions, tho the later are usually wrapped up in rumor as much,or more, than fact), some basics on how corps operate, what kinds of stuff each one does, and so on.
For example, the last time around, Ares talked about being "The gun corp", but also took time to note that this was only a small part of the overal package... AresSpace is one of the biggest off-planet corps, for instance, while Ares Global Entertainment was the #2 entertainment corp in the world before Horizon was born, Ares Consumer Products makes all kinds of stuff (Apple, for instance, is one small subsidiary of Ares), some talk about Knight Errant, and more. You had write-ups of Damien Knight, Arthur Vogel, and a few other power-players in the mix. Oh, and they might have mentioned bugs in there someplace. Maybe. Once or twice.
This time around, who knows? Who's still alive? WHo's dead? Heck, who's in the middle of dying? How's business doing? Are there any new products? (Ares was rolling out a small run of Amber Gel a year ago, was it a hit?) TONS of stuff to cover.
And that's just the Big Ten. If there still *are* ten Triple-A corps, that is.
You should find at least one plot hook on every page, and just getting to know how each corp operates can really help you out in terms of making future runs.