Web Component Developer exam, as name suggests, tests knowledge about designing, developing and deploying web applications using
Servlets and
JSP. It is more logical to take this exam after SCJP unless you are/want to be only a desktop application developer.
Certifications in general are an opportunity to refresh subject knowledge which in turn help you to do your job in a better way.
Of course, they always look good on your resume.
I have been working in
Java web development for the past 6 years. When I prepared for my SCJP (new version), in Feb, I was surprised to see many subtle issues that were not on my radar.
[ April 17, 2007: Message edited by: Sri Kan ]