Two guys who know a thing or two about web services and APIs think the new Google Search API is a step backwards.  I agree.

My guess is that some high up at Google thinks of it as a step forwards.  Perhaps someone asked the question:

Why are we providing search results into arbitrary applications, when in fact, we are in the business of serving ads on Web pages?

An AJAX-only API is a fine way to do just that; but like Don Box says:

No matter how you define “web service,” I don’t think this newest offering qualifies.

I’m hoping this is just an anomaly and not a trend, lest we all fall back into the world of opaque/closed protocols.

Google doesn’t have to provide open and interoperable APIs to the world; but, I bet others will.