Handle deferred models when getting the identifier.
When faceting nested objects, only use the outer most parent object to get the facet name. This is ES specific.
Support having both ES 1.x indexes and ES 0.9x indexes running concurrently, which is very helpful for migrating an index.

Also, try being a bit smarter about when to sending a new mapping.

When applying narrowing date filters, filter all of the results, not just the facets.

Addd the ability to pass a dictionary to ES.

Pass back the search size even if it's zero.

Add the ability to not store everything.