A few new features have been squeezed into Google Finance from what I can tell -- a suggest feature, and live updates on the main page.
When typing a stock or company name into the search box, you are given a list of companies that match what you have typed so far. A similar feature is available for other Google products, but this is the first one to be enabled by default. For news, you have to add an extra query string parameter (news.google.com/news/?complete=1) and for search you must use a Labs project (labs.google.com/suggest).
The second update gives us live updates for the indexes listed on the main Google Finance page. I couldn't reproduce the same behaviour while looking at specific stocks -- which I think would be cool. To see an example of what can be done, MarketWatch.com has inline prices on their articles that are constantly updating.