Foote Partners has noted that noncertified Linux professionals make more money than their certified peers.
This possibly may be a reflection that the market is able to separate the wheat of real-world experience from the chaff of a paper certification, but SearchEnterpriseLinux collects a few other opinions:
Bernard Golden, CEO of the open-source software systems integration firm Navica, says the trend is very interesting but ultimately makes sense. While he recognizes that there is a need for certification and that certification is still very much in demand by both organizations and professionals, Golden points out that certification is only good for demonstrating ability in established, commodified skills. The job market has shifted away from "standard-issue stuff" in the industry, which demanded basic skills from large numbers of employees, and Golden said those days are long gone. Drawn to certified credentials are organizations that still require professionals who can perform basic skills (cost centers, for example).
This rings true. We're in a transition point within the industry, where innovation (in both technology and business models) is roiling traditional measures of competence. There is no certification in "disruption." There also is no certification in "open-source development," which is where some of the best Linux people hone their skills.
Someday, there probably will be. But we're still years from being as boring as 20th-century software. Give us time. One day we, too, will be old, creaky, and expensive. :-)