Following the June announcement by the researcher that reverse-engineered an older version of the Skype protocol, various bits of technical details and code examples were published. Skype went after this work with DMCA take-down notices. When Skype informed me that they were going after those responsible for the work, it was described as "unauthorized use of our application for malicious activities" and "infringes on Skype's intellectual property."
The skype-open-source blog is now dormant. The last status update was in early October, with the only posts since then being unrelated (a Christmas tree photo and a post regarding the end of democracy in Russia). The open-source Skype code is housed on GitHub and there hasn't been any activity there in eight months. The Git repository itself is also empty.
While not as good as a proper open-source client, at least Skype for Linux has SkypeKit with a set of exposed APIs for external applications.