I was privileged to be one of the technical reviewers for this book. There's a fair bit of the original content (which is still great), but Kernighan's done a great job with some good restructuring and some significant updates, too. The early chapters are very hands-on, with something of a focus on "exploratory data processing", particularly with CSV files. Big data with AWK, you could say.
Gawk and awk will soon have a new "--csv" option that enables proper CSV input mode (parsing files with quoted and multiline fields per the CSV RFC). I'm really glad Arnold Robbins added a robust "--csv" implementation to Gawk, too, because that's really the most-heavily used version of AWK nowadays. I've already got CSV support in my own GoAWK implementation, and I'll be adding "--csv" to make it compatible.
I'm really glad this new updated version is coming out!
Ben is not just any old technical reviewer. He wrote a version of AWK in go and has done a ton of other work in the AWK ecosystem.