New version of Mango modifies the Event object to add a "type" field. By default, not specifying a type makes it a blank string. I think Flowmix could make use of this type- specifically in things like filters and stream splitting. I imagine a SQL dialect that could treat event types like tables:
SELECT * from people WHERE ....
Basically this would create a new stream with a filter that would send all events type "people" into a flow where another filter downstream would only return those people matching the contents of the WHERE clause.