In 2007 we extended our hardware inventory to include some custom registry keys. We did this by editing sms_def.mof and configuration.mof. During the migration from 2007 to 2012 is that information migrated. We have several collections based up on this
custom information and we want to make sure it moves over before we start moving collections.
It is not migrated by the wizard, so you will have to extend the inventory manually. You can import a .mof file to more easily extend the hardware inevntory. For more information:
http://technet.microsoft.com/en-us/library/gg712290.aspx