Hans,
I would agree with you to a point that Metapedia should be the single view of metadata, as a 'glossary of the business'. However, I think that objects that are used in a Universe Object should have a name that exists in the glossary. The description of an object should appear in Metadata Management.
There is an idea in the SAP portal for populating objects from Information Steward terms, however I do not believe SAP have picked it up yet.
Aligning the actual approved terms/ descriptions from Metapedia has been difficult. We forward generate the tables from ERwin, often without the metadata and then create a universe. Now if you use UDT and the Metadata Exchange, you can bring in the descriptions but this is not available in IDT.
I'd be interested to know how you go.
regards
Adrian