The OpsManJam site has added a MPViewer dump folder in the library.  While we are just starting out, what you will find here are MPViewer (thanks Boris) extractions of all the Microsoft published management packs as HTML pages.  You can use this as a reference for what is in management packs.  We will be updating this regularly as new versions of Microsoft mp's and new Microsoft mp's are released.  Check it out here.

Chris