Yeah this update seems to be bloating over the borders of caravan arc, and I love it!
The caravan stuff never sounded too interesting, but this sounds like lots of fun!
Well the Caravan Arc gets us more realistic supply/demand economic activity, and all sorts of economic activity happening in-game post worldgen that we can see and interact with in Adventure mode(plus Fort Mode of course). This means lots of Fun! "economic" sounds boring...until you remember that "economic activity" basically means "all activity". Its the reasons that stuff happens in a real world. So with a dynamic in-game economy post-worldgen we go from a static world with a few canned quests and fake trade activity to a dynamic world that you can interact with and impact dynamically, while still being able to do the canned quests if you want. (though eventually I assume the goal is to not have any canned quests at all, ideally things to do should just arise automatically from out of the simulated game world without needing to be canned)
In Adventure Mode terms, when the Caravan Arc is done we get caravan raiding or protecting, trading(everything from running your own caravan to building up a world-spanning trade empire, big interesting towns/cities with tons of stuff to do in them, seeing NPC's actually do stuff as you move around in Adventure mode, buying and selling property(build up a real estate empire?), building your own locations, more sophisticated companions and hirelings etc. All the stuff from the Caravan Arc dev page.
Then later the 'Army Arc' gets the political entities in the game to actually start struggling for control over all of this, with we players getting to play a larger role in that stuff. I shiver at the possibilities.
Anyway I'm rambling, preaching to the choir here mostly I suppose
This was supposed to be a couple sentences and it grew out of control. I do get excited about the possibilities.