Opera 10.52, the newest version of the Opera web browser, was released for Mac OS X, and the latest version of the browser looks like it came straight out of the Apple design team lab. The browser also has some nice improvements that include speed boosts, more HTML5 support and better integration with the Mac OS platform. It is worth noting that Opera was one of the first to broadly support emerging standards for HTML5 and CSS 3.
There have been some smaller usability updates as well, including the ability to search your bookmarks and history page as you type--similar to Firefox.