Management Pack schema file (.xsd) is made available as part of the System Center Service Manager 2010 SP1 Product Documentation package.
"This is useful for any dev that is creating management packs by hand in XML in Visual Studio since it will provide for Intellisense support and real time schema validation," Microsoft stated.
System Center Service Manager 2010 SP1 provides an integrated platform for automating and adapting your organization's IT service management best practices, such as those found in Microsoft Operations Framework (MOF) and Information Technology Infrastructure Library (ITIL).
It provides built-in processes for incident and problem resolution, change control, and asset lifecycle management.
You can download System Center Service Manager 2010 SP1 Product Documentation Microsoft Download Center.