He said the update was rolled out around 3 or 4 AM EST yesterday. Matt Cutts later confirmed the news in a blog post. Because it is only live at one data center, only a small number of Google users will experience Caffeine.

Although both Cutts and Google have indicated that there would not likely be a noticeable difference in search results, Schwartz says that any time the content in the index changes, the results will change as well.

In 2003, Google issued its Florida Update around this same time of year. Merchants and retailers were hit hard since millions of listings from the search results were reportedly dropped. Schwartz believes it is for this reason that Google is only releasing it to one data center. In his blog post, Cutts also assured users that the full launch would not take place until after the holidays.

While the location of the data center was not revealed, Schwartz expects webmasters to determine the specifics very soon.

What do you think about Google’s Caffeine update? Have you tested it? To what extent do you believe the search results will be impacted?