Apple had also added Bing Search in Safari 5.
And the most important feature that is added to Safari 5 is Safari Reader,
Safari Reader removes annoying ads and other visual distractions from online articles. So you get the whole story and nothing but the story. It works like this: As you browse the web, Safari detects if you’re on a web page with an article. Click the Reader icon in the Smart Address Field, and the article appears instantly in one continuous, clutter-free view. You see every page of the article — whether two or twenty. Onscreen controls let you email, print, and zoom. Change the size of the text, and Safari remembers it the next time you view an article in Safari Reader.
Safari 5 uses HTML5,HTML5 features that allow developers to create interactive content and media experiences that work right in the browser — without the need for third-party plug-ins.
You may use following link to download Safari 5:-