Today Stanislav Zhelyakov [http://cloudadministrator.wordpress.com] published v2 of his PowerShell Script.
In short the script grabs the names and the links for all management packs on the site. Than it goes trough every MP link. From every MP page gets the version of it and all download links (msi, guides and etc.). Than creates a directory for that MP and subdirectory with the version number and downloads all files in it.
With these improvements you can run the script with schedule task and configure SCOM to monitor the log that way you can get alerted when new MP is available. All thanks to Anthony Bailey.
You can find the PowerShell script here.