Has anyone written or run across a more Powershell-ish way to work with Tivoli than its traditional tools?
I don't know anything about Tivoli. I did find this: http://www-01.ibm.com/software/tivoli/resource-center/security/code-access-mgr.jsp
So, what Tivoli product are you looking to manage? Try to find information about .NET support or SDK documentation for the particular product you're interested in.