Is a SERP (search engine result page) API a good idea? I think it could be so long as the corresponding results are easier -- not harder -- to digest than they are now. Google does have co-op, which is a SERP API of sorts, but it is quite limited.

Quoted: If these scenarios were possible, then you might argue that all the smart stuff that Google's doing to improve their SERP (seach engine result page) - like making YouTube video thumbnails, or Google Image Search shortcuts - could be done automatically by the people building the underlying sites and integrating with a SERP API.
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Without this, the SERP is a walled garden platform that gets slow, incremental features based on whatever Google chooses to implement. And that's the furthest thing from open, yet it's also not Googley to let people clutter up the SERP. So we'll see how this tension evolves over time ;-)

Makes sense to me...

Quoted: "Rather than struggling, as it currently does, to design sites that meet each end-user need, it should focus on creating a simple, reliable and publicly accessible infrastructure that "exposes" the underlying data," says the draft version of the article (emphasis theirs). In other words, the government should become a data platform, exposing their vast amounts of data to the public -- i.e., via API -- and let the private sector mash it up to make helpful services for people.