Interesting topic. Here is my $.2
I think there is a point missing here, what about "experience"?
Certification should always be back by experience. In obtaining a cert., you are telling your target audience (employers) that you know the technology well and you can apply everything about it to help the company. Cert. is different than a degree. So I would suggest the following:
-if you have experience with web services and SOA, then give SCDJWS. It is an eye catcher for employer really. But at the same time, you should have experience with web development, that's part of what SOA is based on.
-if you have experience with web app development only, then give SCWCD. I just did it. It's cool
and will give you a bigger tool set for doing what you're doing.