The company officially unveiled it to the press yesterday in California:
"It is really big," said Google search executive Amit Singhal.
In fact, Singhal said that what Google has done is the equivalent of switching out the core "engine" of Google's search system for a new one. It's perhaps the most significant change since 2001, according to the Search Engine Land blog.
But the new algorithm, nicknamed "Hummingbird," has been operative for a month now, and yet few noticed. That means it's basically a huge success. The last time Google made a slight tweak to its algorithm ("Panda"), in order to weed out spam and scraper sites, many mainstream web publishers screamed in protest as the search traffic they were used to receiving began plunging.
The fact that few have been screaming tells you that the new algo is doing exactly what Google wanted it to do: Work seamlessly.
You can get more details on conversational search here.
One last thing: At least initially, Hummingbird feels a bit like Facebook's Graph Search, which is designed to handle more abstract or "latent" search queries such as "What movies do my friends like most?," where users do not necessarily know what they are looking for.