Google found a way to promote the not very popular Google Finance: link to it everytime it may be useful to find more about a company. After adding a Plus Box in the search results, Google News shows the tickers for companies mentioned in news articles.
In a recent Q&A, the product manager of Google Finance said that "Google Finance is most different from others in its approach to search. We've tried to make searching for financial information as easy as possible so you can search by public or private company by name or ticker, mutual funds, etf's, even by product or management name. We do other things differently, too, but I think search is the biggest differentiator."
Google Finance seems more like an add-on for search results than a destination for financial information.