The problem with that book is that it only covers MIDP v1.0. Also, it does not cover MMAPI and WMA, which are key components in the exam. I do not think they used standard tools from Sun (Although you do not have to use Sun WTK to study for the exam, it makes your life easier).
The best book that covers MIDP v2.0 is
Wireless Java: Developing with J2ME, Second Edition by Jonathan Knudsen
Addison-Wesley's "Programming Wireless Devices with the Java(TM) 2 Platform (Micro Edition)" (2ND EDITION) covers MIDP v2.0 as well. But somehow I cannot find it on amazon.
However, neither book covers MMAPI and WMA. I discussed WMA in my book
Enterprise J2ME. But my book is more of a J2EE/J2ME integration book. It covers more advanced topics than the exam objectives.
[ December 30, 2003: Message edited by: Michael Yuan ]