The series of articles on PowerShell workflows that are appearing on the Scripting Guy blog is now complete.
The articles in the series that have been published are:
http://blogs.technet.com/b/heyscriptingguy/archive/2012/12/26/powershell-workflows-the-basics.aspx
http://blogs.technet.com/b/heyscriptingguy/archive/2013/01/02/powershell-workflows-restrictions.aspx
http://blogs.technet.com/b/heyscriptingguy/archive/2013/01/09/powershell-workflows-nesting.aspx
http://blogs.technet.com/b/heyscriptingguy/archive/2013/01/16/powershell-workflows-job-engine.aspx
The series is complete for now but as workflow is such a new topic expect more on it in the future.
Until then Enjoy!