Interesting article. Especially to see how many experienced people are opposed to certification exams. I guess the thought of having to sit an exam in something you've been practising for years can be a bit daunting.
I've been in IT for over 18 years now but have had little to no exposure to Java, OO, or web-based development. Aiming for SCJP2 was a very organised and structured means for me to become acquainted with all this new stuff. The certificate itself was just a cherry on the top. I'm starting SCWCD now, and the feeling is exactly the same, not to mention the fun of learning and hanging out at the Javaranch website to boot