The 2nd edition is now with the graphic designer, and should be printed up by early April. It is a significantly different book, most notably because the printed book will only contain exercises, the lessons to accompany the exercises being freely available online. To learn more about the second edition, please have a look at the relevant page indicated above.
As well, the book will contain over 20 pages of HL Paper 3-style questions. As I have been asked about these questions a number of times in the past couple of months I have decided to release them (with solutions) later this week or early next week as an e-book to help students prepare for their exams in May. When I have successfully loaded the book up onto iTunes I will let you know.