If there were an ODBC connector to the Metadata storage structure, use, and maintenance of metadata would blossom.
Currently Metadata can only be edited manually in the ArcGIS environment, and can only be viewed one data set at a time. This "stand-alone" structure prevents use of the wealth of data tools available to table structure data, including bulk and auto editing, and most important: aggregating data.
Example 1: I would like to be able to query a table containing a record with metadata attributes for each data set in a collection of GIS data to produce a data catalog that would be up to date with all the metadata of each layer, so that data could be entered once, and viewed or replicated as any tabular data can be. Having an ODBC connector to metadata would allow it to be treated as any tabular data.
Example 2: I would like to be able to do bulk updating of metadata for layers that share the same values for certain metadata attributes, or whose metadata attributes can be calculated from other existing data. This would be especially useful for derivative data, such as all the flavors of parcel data we have that share certain origin and field description data.
One of the most important principles of GIS is that all the map information exists in tables, which exposes that information to all the power of a multitude of tools that work on tables, both inside ArcGIS, and outside of it. This is what make GIS such a powerful and flexible tool. If that same tabular access could be made available to metadata, there is so much we could do using all the available tabular tools.