I say now for Linux, but I missed the boat on Windows PowerShell Desired State Configuration all together! Given the flexibility of PowerShell, it should be no surprise that you could write your own configuration management scrips but Microsoft has taken some of that work of your plate with for both Windows, and as of TechEd last week Linux.
DSC is a set of cmdlets to control things such as server roles and features, directory structure, software deployments and much more. The Linux version of PowerShell DSC (currently in technical preview) will also allow you to manage things such as scripts, services, users and groups. I can see this being a life saver for Windows shops making the move to opensource / linux services or for administrators who want to advance their linux skill set.