Just to add (following from your title "Has SUN produced the official study guide for 1.5?"), there are no official guides promoted/marketed by Sun. The book you mention is just one of a handful of such study guides. Check the SCWCD 5 Links for books written for the exam (which is no different in material from the old exam).
Charles Lyons (SCJP 1.4, April 2003; SCJP 5, Dec 2006; SCWCD 1.4b, April 2004)
Author of OCEJWCD Study Companion for Oracle Exam 1Z0-899 (ISBN 0955160340 / AmazonAmazon UK )
Joined: Jun 28, 2006
Thank you for your clarification and info, Charles!