editing because a thought just occurred to me. i believe DS9R is about 3 or 4 years behind TNGR. i think in the TNG books they act like they haven't seen the borg since first contact and the voyager stuff so i don't think it would make sense for a DS9R borg book to come out.
Well, the last Borg encounters prior to the TNG-R were "Endgame" and Homecoming/The Farther Shore -- the end of 2377 to the start of 2378. The DS9-R is currently at the very beginning of 2377. So theoretically there's room for DS9 to do something with the Borg within that one-year interval.
However, I don't see any compelling reason to do a Borg story in DS9. It's a big universe, so everything shouldn't have to cross over with everything else (except in very extraordinary cases like Destiny).