I would really like to see Paizo do at least a one-off modern/sci-fi RPG based on the Pathfinder rules. I even have the perfect name for it, which I have suggested on Twitter a few times. I think though that it might be better to take what works in Modern and add it to the core Pathfinder system rather than the other way around. I kind of wonder whether they just have zero interest in such a project, or perhaps they are holding off until they can make it the introduction to a future "Pathfinder, 2nd Edition" . Especially after the Ultimate Equipment and Ultimate Campaign Guides though it seems like the time could be right to give it a shot.
Well, they haven't even done a second campaign setting yet (not that they necessarily will, but it seems a smaller goal than an entire new game).
Then again, who knows? For all we know they might announced Pathfinder 2nd Edition or Pathfinder Modern at Gen Con. I'm not holding my breath though!