Some people just use the 1.4 book and learn the new stuff from elsewhere. Some buy the 1.5 book anyway. I suggest that if you are taking SCJP 5, use the java 5 book by kathy and bert. To understand the complexity of the questions that can come under newer topics like generics, its a good book to refer.
If this is not your cup of tea feel free to study from the 1.4 book but make sure you cover enough tutorials about topics like generics. Dont forget to take mock exams that cover these new topics to know where you stand.