Fellow SQL Server MVP Jasper Smith has come with a really neat tool named “Reporting Services Scripter” that makes managing multiple Reporting Services installations easier. It enables scripting of all Microsoft SQL Server Reporting Services catalog items to aid in transferring them from one server to another. It can also be used to easily move items on mass from one Reporting Services folder to another on the same server. Depending on the scripting options chosen, Reporting Services Scripter can also transfer all catalog item properties such as Descriptions, History options, Execution options (including report specific and shared schedules) and server side report parameters.
You can download the Reporting Services Scripter here.