exam offered by the major test tool vendors should not be "too easy." The entire process should thoroughly challenge your knowledge of the software. I would personally like to see a joint venture between organizations such as the Quality Assurance Institute and the major test tool vendors. A standard core curriculum and adaptive strategy to certified quality assurance professionals in test automation could be developed. For example, just as someone could earn an MCSE + Internet certification from Microsoft, QAI, or ASQ (or some other QA certification body), something like the Certified Software Test Engineer (CSTE) + "[X Test Tool Vendor]" could be offered. This would allow one to gain specific knowledge in a particular area (i.e., capacity planning, performance tuning, etc.) using a particular test vendor's tool.
In addition, a test tool vendor certification should not saturate the market, as the Microsoft Certified Software Engineers (MCSE) did. The easier the process, the more "paper certified" individuals there will be in the marketplace. There should be a continual effort by all vendors to update and improve their examinations. The more challenging the process and exam, the more confident you will feel that the certification process was worth your time and effort.
Should you get test tool certified?
People have to answer this question for themselves. My opinion is that anything one does to improve oneself is worth the effort. The litmus test of certifications is one's ability to implement those skills on the job. The certification does not make you better than the next applicant. Education for specific work happens on the job and it is a continual process.
Another question one should ask is, "Why get the test tool certification in the first place?" Is it to secure a new job, improve your skill set, increase your knowledge with a tool, or increase your income? Probably the broader question is, "Will anyone care?" Perhaps most important, will you care?
As a child my mother and father always taught me to never stop learning. The ultimate goal should be self development. Carefully examine test vendor certifications and see if they are right for you. Will you learn more than you know already, or are you just getting a stamped piece of paper? What is your opinion?