Update: Matt Cutts from Google confirmed that Caffeine is live 50% of the time in the 209.85.225.103 data center. See below for more info.

There are several threads reporting major changes in the Google search results, starting yesterday. We have threads at DigitalPoint Forums, Google Webmaster Help and an updated WebmasterWorld thread.

In short, people are noticing major changes in the search results. Some believe it is a Caffeine index rolling into their search results. Some believe it is just a normal update and not Caffeine related. We do know that Matt Cutts promised not to roll out Caffeine until after the holidays and a roll out at this time would be the worst possible time for online retailers (unless you rank very well in Caffeine.

We also know Google is eventually rolling out Caffeine to a single data center, which can be why many people are noting an update. But again, it might be that these folks are on this single data center or that this is not a Caffeine update. I certainly hope this was not a mistake and Google released the Caffeine update prematurely.

The data center people are talking about now is 209.85.225.103.

People are saying that their traffic is down because of it, but some are also noting that it is/was Thanksgiving yesterday, which can result in people not being on their computers searching Google – thus less traffic from Google.

Forum discussion at DigitalPoint Forums, Google Webmaster Help and an updated WebmasterWorld.

Update from Matt Cutts: