I also think it's worth pointing out that Zero Sum Game does end with "THE SAGA OF DEEP SPACE NINE WILL CONTINUE
". So obviously the Typhon Pact books aren't intended as to be the end of the DS9 series.
And while I would love to see the post-finale characters return, I'm still open to reading a Deep Space Nine series following Capt. Ro and her DS9 crew. As unhappy as we might be with the fact that they've moved alot of our favorite characters into different places, I don't see any reason to believe that we can't be introduced to a new group of characters who could become just as beloved as the characters introduced Avatar. And so far none of the existing characters have been put into a place where they couldn't continue to play a supporting role.
I keep hearing people calling Vaughn dead, but that is not the case. I just reread the last scene with Vaughn and while they did remove his respirator, and discussed removing his feeding tube, at the end of the book he was still alive. And until we actually "see" his dead body, and are told point blank he is dead, I'm not gonna write him off.