Kingmaker's not yet out... but I'm about to start work on developing part 3, and I'm REALLY pleased with how it's turning out. It's pretty different from our normal model for adventure paths, so I'm eager to see how folks react to it. In a nutshell, Kingmaker is our response to the claim that Paizo Adventure Paths are too linear and not sandboxy enough. The fact that PCs build and run their own kingdom and cities should be pretty interesting as well...
That sounds intriguing, as I'm looking to start a new campaign in the coming months and was hoping to make it a bit more open-ended than the last one (which was kind of open-ended in the beginning, but once they learned about the prophecy, it kind of fixed them on the end point even if they had different options of how to get them there...)