If people were already seeing different search results from one another before, that is really going to be true now, now that Google is plugging results based on the individual’s social circle into any given SERP. This is one of the many ways SEO is changing, and it would appear that any business looking to get some play in Google search, would do well to have as many connections established as possible, via various social networking sites and tools.
http://www.webpronews.com/topnews/2010/01/27/google-makes-social-even-more-of-a-search-factor