http://www.microsoft.com/downloads/details.aspx?FamilyID=a24cea3a-1920-4b18-8cf2-8bf78c94c917&DisplayLang=en

The Microsoft® Management Pack Notifier Management Pack enables the generation of Informational alerts as updated management pack are released.

Once installed this Management Pack will periodically contact Microsoft to determine if updates to previously installed management packs are available for download. When an update is detected an Informational alert will be generated indicating which management pack(s) and version(s) are available.