Non-SQL databases and the Zend_Db namespace

Hi everyone,

Currently I'm in the process of writing up a simple proposal for Dbm-style 
databases (Berkeley DB, GDBM, etc.).  The description for Zend_Db and 
Zend_Db_Adapter_Abstract both say, "Class for connecting to SQL databases 
and performing common operations."  But there are other types of databases 
besides SQL: key/value pair (Dbm-like), XPath-based, object-oriented, and so 
on.
So where do the adapters for the other types of databases go if not Zend_Db? 
If someone wanted to create a read-only dBase adapter, where would it fit? 
Creating multiple top-level namespaces is sloppy from an organizational 
point of view as well as unintuitive for users.  For that reason I propose 
that the current Zend_Db_* hierarchy move to Zend_Db_Sql_*.  This way, we 
can keep abstract functionality in logical places: Zend_Db_Xml_Adapter_Db2 
(IBM DB2 9), Zend_Db_Xml_Adapter_Berkeley (Berkeley DB XML), Zend_Db_Dbm, 
etc.
It might be a bit painful to do now, but I think the need will come up again 
later.  If it's closer to 1.0 then it will be much more painful.
Thoughts?

-Matt