Note : This tool is now at v2.5 and is compatible with System Center Orchestrator : See http://blogs.technet.com/b/yasc/archive/2011/12/13/orchestrator-remote-tools-2-5.aspx. You should stick with the Opalis UI Generator 1.1 if you are using Opalis though, as the new 2.x versions are for Orchestrator only.
Here is v1.1 of the Opalis UI Generator. The main new feature is an easier to use tree view when browsing for policies.
Planned in next version is a command-line version of the trigger tool, in addition to interactive and web triggers.
Again, feedback is always welcome :-)
Update : This is also available on CodePlex : http://opalis.codeplex.com/releases/view/57082