From where I sit, the most dynamic trend in evangelicalism today is the re-energized Reformed movement. I ran across an old post by Justin Taylor that brings together some resources analyzing the movement. They’re all by people inside the movement (Mark Dever, Trevin Wax, and Collin Hansen), but they’re valuable nonetheless.
As Joel noted some time ago, Molly Worthen is doing some valuable analysis from outside the movement.
She has a book coming out this year or next year.
Is it on the Reformed movement?
I can’t remember, but I think it is about evangelicalism more broadly.