Version 2.6 of the PDT has been released with some updated features. You can find the blog post for its release here.
When ever Rob releases a new version the first thing I do is update my XLS with the list of variables that are available so I can see what has changed and what new options now have. Here is a copy of my XLS.
There are 3 tabs one that lists all roles that are found in the workflow.xml, One that lists all the variables that are found in the workflow.xml and one that lists variables that are used in the VMCreator.ps1 file.
Hope it Helps.