Here is a brief description of how I look at Various certificates mentioned. The perspectives might differ from person to person.
SAS Certified Base Programmer for SAS 9
This is a basic certification. The way I see it is that the person with this certification would know how to do data massaging in SAS - so he can be handy for SAS reporting and data manipulation. This is also relatively easy to get and does not carry a lot of weight (compared to some other certificates mentioned here).
SAS Certified Advanced Programmer for SAS 9
This is where SAS programming gets serious. People with Advanced SAS Programmer certificates are people who can look at your code and optimize it. They would know nifty hacks to use the system more efficiently. It your needs are reporting / dashboarding / automation on SAS, you will find these people good with their work. However, if you want to get a predictive modeler - this certification would not help much.
SAS Certified Clinical Trials Programmer Using SAS 9
This is specific to clinical trials - I am not the right person to comment on this.
SAS Certified Predictive Modeler Using SAS Enterprise Miner 7
One of the most looked up to certification from SAS. As the name says, the certification covers several modeling techniques using SAS Enterprise Miner including clustering, Neural networks and a lot more. People with predictive modeler certification also find their way on the listing on SAS website and are typically seeked in industry.
SAS Certified Statistical Business Analyst Using SAS 9: Regression and Modeling
A person with this certification would know basics of predictive modeling including Linear and Logistic regression and possibly ANOVA. He may not know a lot of algorithms, but would know a handful of them and can be trained into a predictive modeler over time.
SAS Certified BI Content Developer for SAS 9
Not entirely sure, but this would be helpful for companies on SAS BI platform. I am assuming the person will become proficient in creating OLAP cubes and other components for the SAS BI platform.
SAS Certified Data Integration Developer for SAS 9
Probably most helpful on the ETL side. Again doesn’t carry much benefit on the predictive modeling side.
SAS Certified Platform Administrator for SAS 9
As the name suggests, this certification is for admins - so you should undergo this, if you are already an admin or are planning to become one.
How they can be helpful, depends entirely on what you want to pursue. If you want to become a predictive modeler - Base SAS should be a given, Regression & modeling certification would meet the expectation of the role and Predictive modeler on E-Miner would double up your chances, if the employer uses E-Miner.
Hope this helps