It looks like this is coming in the next IDP release (4.3).
There is some information about portal content promotion in the SAS® 9.2 Intelligence Platform: Web Application Administration Guide, Third Edition. You can find it in Chapter 20 Introduction to SAS Information Delivery Portal Administration under Main Tasks for Administering the Portal (http://support.sas.com/documentation/cdl/en/biwaag/63536/HTML/default/viewer.htm#a003135944.htm) in the section named Promote Portal Content. It states (in part) “Beginning with SAS Information Delivery Portal 4.3, a content promotion tool is available. This tool consists of stand-alone batch scripts, shell scripts, and metadata extraction templates.”
As Paul mentioned, there is a tool included in 4.3 to do this. That same tool can be used today and SAS doesn't widely promote it (and I'm not sure if it is currently "supported"), but contact Tech Support and they should be able to provide access to it.