The Reader feature is interesting, and it shows great room for improvement. You just have to click the “Reader” button up in the address bar (or press ⇧⌘R) to tell Safari to extract text from an article, and it will display it just fine in a modal window that dims the original page. Like this. You can increase and decrease the font size in this window, email the article and print it. These shortcuts are useful.
via macstories.net
Those who use Instapaper will find the Reader similar. Safari 5 provides HTML5 support and allows extensions. Can't wait to try it myself.