A beta version of Opera's next major version, 10.5 has been released. They advertise it again as "The fastest browser on earth", and this time it seems not without merit. I've used the new beta for a few hours now, and it's lightning fast even in normal browsing. Out of the browsers I currently have installed(FF 3.5, Chrome/Iron 3.0, Opera 10.1 and Opera 10.5) it's easily the fastest. It looks like all the tabs are also finally in separate processes, so if one tab crashes it shouldn't bring down the whole browser
http://www.opera.com/browser/next/