The new beta version isn't only packing the WebKit engine, but a complete redesign of the browser's UI for Android. The Speed Dial page has been redesigned with new page icons and folders. There is a new Discovery page to go along with Speed Dial that can help you find new content on the web, and you can customize what type of content shows up there. And, Opera has added Turbo, which allows data to go through Opera's proxy and be compressed for faster speeds. Although, it has been rebranded "Off-Road Mode"; a change seemingly for the sole purpose of being able to use the tag line "It keeps you connected and loads webpages faster when conditions get rough."
The browser performs quite well, and scored an impressive 450 on HTML5test.com, which is well higher than Google Chrome (417). It's definitely worth a look, especially if you're not too tied to the Chrome syncing features.
Opera beta is available for free in the Google Play Store.