The new edition of Mastering Regular Expressions sounds amazing. The first edition was very informative and interesting, the new edition sounds even better. Yay.
The O'Reilly sites advertising says,
Mastering Regular Expressions, Second Edition has been thoroughly updated to include all the new features of Perl 5.8, as well as several other languages, including Java, VB.NET, C#, Python, JavaScript, Tcl, and Ruby. Written in the lucid, entertaining tone that made a complex, dry topic crystal-clear to thousands of programmers, and sprinkled with solutions to complex real-world problems, Mastering Regular Expressions offers a wealth information that you can put to immediate use.
It all sounds true. Go and buy it already.