I found this ping-back on my previous blog post which gives a good overview of one very useful cmdlet that we ship with the Powershell extensions that SQL Server 2008 will deliver. A very helpful article one of the SQL Server MVPs, Lara Rubbelke, on the use of Invoke-PolicyEvaluation:

http://sqlblog.com/blogs/lara_rubbelke/archive/2008/06/19/evaluating-policies-on-demand-through-powershell.aspx