Boris Schapira takes a look at the Speculation Rules API that we just had a poke at around here. Boris notes that this idea of prefetching (or prerendering) the next page that a user might visit has quite a history. One of the players in this game, which is still a pretty good choice as it’s more cross-browser compatible than this new API is, is instant.page, which I’ve used many times successfully.
Note that the Speculation Rules API is not yet a web standard, but the way it works has so little negative implication on browsers that don’t “support” it, it feels pretty safe to use. We put the WordPress plugin in place around here.