The title is very intriguing, but ... This book is overview which shows general trends and that's it. Some parts/chapters were redundant.
Part 1: Developing with Java 7. It was really interesting. Nothing to say.
Part 2: DI, Concurrency, class file, bytecode, perf - all these are just overview but very interesting. You won't be well grounded after reading this part ;-)
Part 3: There was a try to highlight basic features of Groovy, Scala, Clojure. But, it's impossible for such different langs using ~30 pages per lang. As for me the most important chap from this past is chapter 07 "Alternative JVM languages". There are nice advices how to pick language from JVM zoology, really useful "cheat-sheet"
Now the last part 4. If you are not familiar with TDD, CI, Rapid web dev, it's for you.
Some tech details are not required and might be outdated right after the publishing. As for me such topics must be on conceptual level only.
More over prototyping in Composure is our of trend. And I don't think that "well" grounded dev should know this, IMHO.