The biggest change that you can actually play with is Reader. You'll notice that the "RSS" button in the address field changes to "Reader" when it's available. With a click, a new window slides up and displays the current article's reformatted text and images. It's printer-friendly, center-aligned and easy to read. From there, you can make the text larger or smaller, print the article or email it to a friend. It's similar to reading an article on the iPad with an app like Instapaper. Additional stuff on the page, like sidebar items, etc. is eliminated.
Actually, the email option didn't work for me. Instead of creating my message, Safari displayed a dialog box stating that I need to install Mail (it's installed). It's also kind of tricky to figure out when the Reader option will be presented. It won't work at http://tuaw.com, for example, but does for individual posts.