Safari 4 Beta tracks the sites you browse and ranks your favorites, presenting up to 24 thumbnails on a single page.You can even customize the display by pinning a favorite site to a specific location in the grid.
Cover Flow offers a highly visual way of reviewing your site history and bookmarked sites, presenting full-page previews of the websites that look exactly as they did when you last visited them.
Full History Search
Safari introduces a dramatic new way to revisit sites, letting you flip through full-page previews of the sites you visited in the past. You may not have total recall, but Safari does, automatically storing all the text and a thumbnail of every page in your history. That makes it easy for Safari to get results even if you remember little about the site you’re searching for.
Tabs on Top
Safari also makes it easy to create and manage tabs. To create a new tab, just click the + button in the upper-right corner of the Safari window.
Windows Native Look and Feel
To provide a consistent Windows experience, Safari now uses Windows standard fonts, but you can choose to use Apple’s crisp anti-aliased fonts if you prefer. Of course, Safari in Windows delivers the same lightning-fast performance provided by the Mac version.
More features : http://www.apple.com/safari/features.html