Full-text indexing (what ES provides) has been around for almost forever, ES just does a way better job of productizing/delivering it.

However, Google is far more than a text index. Ranking, currently is still very difficult and requires messing around with facet and weighting parameters.

In my opinion which means nothing, sites need to figure out how to power their own search. Using a third party isn't going to work for most. Maybe people need to focus on building custom architecture that indexes the data in a more structured way rather than cobbling systems together that ultimately hinder search efforts when its time to get the user what they want. I don't know the answer but somebody eventually will. Maybe wordpress will create a powerful search for all those wordpress sites.