I asked this question. The answer I got from SUN said:
"While certification exams, such as the SCJP 1.4 and SCJP 5.0, are designed to test for specific versions of Java, the SCJD assignment is designed to be completed using a current version of Java. You may actually use either Java SE 5.0 or 6.0 for the SCJD assignment.. Java SE 6.0 was released December 11, 2006, so Java SE 5.0 may be used for the SCJD assignment until June 11, 2008."
So it looks like 1.5 can be used for a little less than 2 more months.
I hope that helps -John
SCJP 5<br />SCBCD 1.3<br />SCJD<br />SCWCD 1.4, 5<br />SCBCD 5 -- working on it