No, I couldn't work out from where that came. The original script is actually full VB - see the following link from MSDN:
Creating a Package and Programs Using SMS Classes

I looked a little closer at PUT_ SWbemObject.Put_ and it talks about this either being blank, or being a value name from a provider that is servicing this request.

It *seems* to work without the rest of the PUT_

code:
$=$oNewPackage.Put_
but I wonder if it's not actually really doing what I ask it to...