Back in August, Google announced the launch of their next generation infrastructure for Google’s search engine index. Google Caffeine would include changes in crawling, indexing, and ranking algorithms which means those changes are only infrastructure related and includes no UI update:

For the last several months, a large team of Googlers has been working on a secret project: a next-generation architecture for Google’s web search. It’s the first step in a process that will let us push the envelope on size, indexing speed, accuracy, comprehensiveness and other dimensions. The new infrastructure sits “under the hood” of Google’s search engine, which means that most users won’t notice a difference in search results. But web developers and power searchers might notice a few differences, so we’re opening up a web developer preview to collect feedback.

As Matt Cutts said, Google Caffeine would be fundamentally a big change for Google and is a complete rewrite of many parts of Google indexing system, which means Google will do everything in their power to diminish algorithmically focused search engine optimization efforts.

The Register offers an article stating the technological background of Google Caffeine and a more comprehensive analysis from SEO point of view has been done by Bill Hartzer and David Naylor.

Google Caffeine sandbox preview was available at http://www2.sandbox.google.com/ , which is currently unavailable and the Caffeine splash page now reads as:

Based on the success we’ve seen, we believe Caffeine is ready for a larger audience. Soon we will activate Caffeine more widely, beginning with one data center. This sandbox is no longer necessary and has been retired, but we appreciate the testing and positive input that webmasters and publishers have given.

The message displayed on Google Caffeine splash page indicates that:

1. Caffeine testing was successful. The project is moving forward.
2. Caffeine is going live on Google.com soon, starting with one datacenter.

As Matt Cutts highlighted, webmaster’s can Expect Caffeine after the holidays. SEO’s, the bottom line for Google Caffeine update is Speed, Accuracy, Temporal Relevancy, Index Size and remember this could allow the search engine algorithms to make SEO more challenging. Here is what John Andrews mentioned on his Google Caffeine SEO Notes:

Smaller chunks means faster SERP generation…. and possibly more specific quality management (smaller more specific binning of URLs if desired) How this plays out for SEO is interesting now… and especially whether or not we will be able to influence various aspects independently from the whole.