Paul Stovell's blog post from December 2012 discusses the new features in Octopus 1.2.2, specifically the support for variable substitutions, which allows variables to reference one another, enhancing flexibility and efficiency in deployment processes. This update enables the Octopus Server to resolve variables by applying substitutions, while also checking for cyclic dependencies to prevent errors. Users can customize the behavior of variable substitutions, such as ignoring undefined variables or altering the default syntax with custom regular expressions. Additional features allow users to verify variable substitution by printing values before and after resolution. These enhancements aim to simplify the process of defining variables during software deployment.