In order to provide a more consistent experience with the System Center product family, we've moved the Orchestrator blog to another blog at http://blogs.technet.com/b/orchestrator. Be sure to go there for all the latest info!
This post has been revised for Orchestrator and moved to the Orchestrator blog here:
http://blogs.technet.com/b/orchestrator/archive/2012/05/04/oit-quick-tip-using-powershell-switch-parameters-in-cli-activities.aspx