Pathfinder Online is still too early in the development process to do much more than talk about principles, but said principles are certainly of interest to fans. The most recent development blog about the project discusses that game's PvE arm, which is meant to be an important part of the game without being the sole driving force. Instead of the game being driven by players going, gathering quests, and then going out to kill monsters, the development team hopes to create an environment where players go out to do something and then find themselves in the midst of a quest.
Four basic types of interconnection are outlined, ranging from wandering monsters to potential beasts attracted by overharvesting an area. (Cut down too much wood in an area and wood-dwelling creatures my start attacking lumberjacks... or some nasty flying monsters might decide the cleared area would make for an excellent nest.) It's certainly an interesting set of principles going into design, making the entry well worth a read for sandbox enthusiasts.