As business entities and Internet-savvy individuals become more aware of SEO (Search Engine Optimization) and its importance, the question of standards and certification becomes much more prevalent. In short, the truth is that there are currently no industry-recognized standards or certifications that qualify an individual or entity as an "SEO Certified Professional."
Despite that fact, there are still well-credentialed establishments who are offering their own flavor of SEO certification. For instance, Bruce Clay, Inc. -- an upstanding and very popular SEO firm -- offers a costly-yet-informative course on SEO which places ethics at the forefront of the discussion. Upon completion of their course, you get a certificate, a badge to add to your Web site, and placement on a roster in which prospective clients can verify your credentials with them.
On the standards end, perhaps the closest thing the industry has to representing a central body is SEMPO. They also offer various levels of certification separated by cost and extensibility. Additionally, several universities (online, especially) and SEO agencies the world over are offering up certification programs like hot cakes. The main conundrum is that -- because there are no standards -- there is no real way to qualify someone to teach SEO to the extent that they can certify others in a manner recognized by one industry-governing body.
Additionally, where standards are concerned, part of the difficulty in defining them can be exemplified by the recent implementation of Google Instant. It alone would have undoubtedly caused a slight shift in the SEO curriculum predating its implementation (once the ramifications of it are fully understood in such a manner that standards could be created based on it), so that right there may have just made re-certification a necessity.
So, while certification is not an industry-recognized credential (or even truly a necessity, for that matter), it can still be a very structured and beneficial approach to learning SEO. Though I'm not confident that we will ever see a true resolution to this, there will always exist the desire to standardize SEO and make it a certifiable entity. Until then, all we have are the bodies of work produced by the most trusted businesses and entities in this industry. Luckily, they aren't too hard to find once you find yourself involved in communities like this blog.
To close, here is a video that Matt Cutts from Google put up on YouTube just the other day addressing an SEO certification question. He fills in some of the gaps not covered within this post and may very well answer questions you may have at this point: Are there any SEO certification programs you are aware of?