I'm not sure how this would work. The uninstall command for each software package is stored in the registry under "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall" and could probably be retrieved by the audit.vbs script (if it is not already).
The only problem would be that the uninstall command would have to be executed on each system with the software installed. If the idea is to do this centrally from a remote location (perhaps doable using psexec) this would require that the account performing the uninstall have local admin rights on each machine. Most uninstallers require some kind of interactive GUI response with the standard uninstall command (which would be a problem if using a command line utility like psexec for example). You could probably get around this if the installer application supports silent uninstallation (i.e. for msi-based packages msiexec /x z:\myMSIfile.msi /q might work). But there are dozens of installer types out there and some make it easier to do silent installs/uninstalls than others. (AppDeploy is a good resource for finding out silent install/uninstall options:
http://www.appdeploy.com/packages/index.asp)
It might be possible to make a list of silent uninstall strings for common applications but from what I've seen the silent uninstall options are a lot less prevalent than silent install options.