The new version of Opera (9.5x, codename: Kestrel) has been released, and one of the stated aims is to improve performance across the board. This has resulted in a new ECMAScript engine and substantial revisions to overall page rendering compared to the previous version (9.x, codename: Merlin). So, using the good old scientific method, we can quantify how Opera's performance has changed.
Internet Explorer 9 beta
Opera 10.70 9048