It looks like xenForo uses an object oriented, design patterns approach, and I like that. It looks like the old hook system is now a system (by enlarge) replaced by extending classes.
So, for the mod I want, I'd have to extend XenForo_ViewPublic_Thread_ViewNewPosts, via the Load_Class_Control code event, and modify the method that does the sql query to get new posts. This is all very slick.
The question I have, is what happens when someone else does the same thing? Execution order will only help you decide which mod wins.
Am I missing something? As I said, new but learning fast.