It seems JCert is a new path for
Java certification but
there are not many people seeking this way. Sun's certification
is well-known and it's enough to be good reference when you
seek Java jobs. I think JCert will be the future way for Java
certification. Actually you only need to get through IBM's UML
test and plus sun'd SCJD then you can get VCSD and VCED.
So go ahead for Sun's certifications.