One thing that I have noticed about these certifications is that they each emphasise a different thing. I have the programmer and developer certifications, and I'm working through the architect right now.
The programmer certification shows that you have a general understanding of the Java language, and can use it effectively.
The developer certification shows that you are able to take instructions and translate them into well tested code, with a lot of documentation that will make your application easy to maintain.
The architect certification shows you are capable of developing enterprise framewords for long term system design.
I think that John has a point in that a lot of developers do not want to do architecture full time. Most people want to stay in the code, etc., etc. While this is all well and good, I personally believe that a good developer is someone who is well rounded, and can both develop a strong architecture as well as program one. Besides, I have worked with some architects that haven't had the most stable architecture, and it definitely helps if you can understand how they are designing the application and spot any potential problems.
I think that the reason that people aren't as interested in the architect certification is because it has recently been changed, and the core of the first part of the exam is on J2EE design, which not many people have experience in. I've developed a few J2EE based solutions, and when I was looking for a new job I had to fend off the recruiters with a stick! The problem is that the J2EE platform is not trivial and it takes experience to understand how it works, plus a lot of very big books. :-)
The programmer certification has a load of books available, and the developer also has a few "prep" books. However, the architect doesn't have any, and most people will be intimidated by that. Well, that's my $0.02 on the matter.
John
