This was first announced in April 2013. Still, it should be worth the wait.
Glimpses inside the book are now available at Google Books here.
Michael Bird has a short review of Bratt's Abraham Kuyper
James Bratt looks at The Twelve looks at what might be an appropriate image for Kuyper's model of Christian engagement. He concludes:
I don’t think we can capture Kuyper’s purpose or legacy in one image. We need to deploy the whole fleet and let people find the one appropriate to their occasion and circumstance. Kinda the way the Bible plays it, no?
James Schaap has some reflections on reading Bratt's biography of Kuyper: here, here and here