Researchers at Penn State have analyzed actual search data and have found a very familiar pattern: IST researchers classify Web searches:
The research was the first published work of its kind done using actual searching data, with the aim of real-time classification. Researchers analyzed more than 1.5 million queries from hundreds of thousands of search engines users. Findings showed that about 80 percent of queries are informational and about 10 percent each are for navigational and transactional purposes.
The results match pretty closely with what we see in user behavior from analyzing the metrics for content rich sites, i.e. not social sites. What will be interesting is to see how these results change over time. Will we eventually see navigation disappear entirely? I'm thinking so. Searchable wads of of content; it makes Google's Knol strategy look all the more brilliant.