If you need to find the schemas that are deployed and their unique root node names you can run this query.
Yes BTS 2004 still exists.
use biztalkmgmtdb
select msgtype as [Schema NameSpace#RootNode],
clr_namespace as [Assembly Name],
clr_typename as [Schema TypeName],
docspec_name as [Schema Namespace.TypeName]
from bt_DocumentSpec
order by msgtype