Finally got a chance to sit down and read the chapter.
I thought it was excellent and Oda is really at the top of his game. A lot of times writers have a hard to keeping the reader's attention after an action filled event like the Marineford Arc, but Oda keeps throwing out nuggets that force you to keep reading.
As others have said, Kong serves as a conduit between the Five Elder Stars and the upper brass of the Marines. It is very common for very large organizations to have a position such as the one "Kong" has. I think Oda showed you that Kong has real authority as he basically tells Sengoku that he cannot retire and forces him to stay in the Marines. Now he was very smooth and passive aggressive when he did it but that was basically what happened.
Boy, the inevitable fight between Koby and Luffy just got a lot more interesting. I believe at the end of the series, Koby will be an Admiral level fighter. I could even see a situation where Luffy and Koby are much like Garp and Ace and Luffy eventually entrusts his child to Koby, but that's just a theory.
Anybody else glad Blackbeard got rid of Capone Bege? Out of the Supernovas, I thought he was the least interesting.
Also, when the Five Elder Stars were asking themselves, who could stop the rise of Blackbeard, why did one of them say, "The Four Emperors", when there is only 3 now?