Google Caffeine’s Pros and Cons
Google Caffeine is the new version of Google search. Google officially calls this the “next generation architecture 
for Google’s web search”.
Google caffeine as what Matt Cutts says, is a rewriting of their indexing system to be able to crawl, index and serve results faster.
“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.”
