As an owner of the previous edition which was based on Java 6 I can only repeat my recommendation for this pocket guide for JAVA 7. As a professionell JAVA developer you will find all keywords, techniques, types and basics of the JVM and the JAVA programming language in one handy and compact book. The information in every chapter is complete and precise.
If you own the previous edition, the updates and additional chapters are not worth the extra money, because the new chapters on NIO 2.0 and the new G1 garbage collector only introduce the topic and then refer to online documentation instead of going into detail. Which is in the end a good thing, because the book itself is about the basics of JAVA and not a detailled explanation of available libraries.
If you do not own this pocket guide at all (this or the previous edition), I strongly recommend to get one, because if you don't know what the modifiers strictfp or native mean, what the difference between checked and unchecked exceptions is, how you pack/unpack JAR files in the command line or what cool development tool you missed for your projects, this book has the answers to all those questions!