I'm just speculating... but 1.4 is still part of the Java 2 platform, so it's still an SCJP2. Unless Sun's marketing calls it something silly like "Java 4" :roll: The certificate says Java 2, not 1.2/1.3/1.4 etc. ---
I just called SunEd to check into this. The guy I spoke to said a certification will never expire, but if a totally new version of Java comes out they will probably offer an upgrade exam. The example he gave was the certification from Solaris 7 to Solaris 8 -- there's an upgrade exam availabe to people already certified in 7.
The certs don't expire as far as Sun is concerned, but which one you have may matter for other purposes. Oracle is one of the companies providing an enterprise developer (i.e. JCert) certification track. The SCJP is required for 'level 1'. Oracle gradually drops the oldest certifications from eligibility for transfer into the program. From what I've read I don't think they get on your case once you are in the program, but when you try to transfer in initially which SCJP version you have matters.