hi om prakash google caffine is just a rookie element of google which was kept in test stage alone . it was not integrated into the standard google algorithm. I had a personal blog whose SERP went up and another one which went bad due to it.You can see some drastic changes in the ways your pages are indexed due to this caffine effect. the following is the link to check abt it from google and it has been un available for a few days. http://www2.sandbox.google.com/ so the last word about it is its down (either temporarily or permanently) only God knows....errr google knows .
It is a different architecture from Google which they are implementing. According to them: "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." You can read more and watch video of matt cutts regarding caffeine update here.
There's no changes on Google's guideline on ranking so still stick with quality and naturality of link building making contents will ensure good rankings. But of course those social networking/media methods are very trendy and surely has affect on rankings too.