"Microsoft is touting the new browser's substantially improved performance, both relative to its predecessor and, thanks to its hardware acceleration, relative to other HTML5-capable browsers. The new version leapfrogs Safari 5 in the SunSpider benchmark, though still marginally trails behind Chrome 5 and 6, and Opera 10.60. Still, the mere fact that Internet Explorer 9 is competitive is a vast improvement. The browser's standards conformance has been improved, too. It now earns a score of 95/100 in the Acid3 test."
This is excellent news. Well done to Microsoft and the IE9 team, since it looks as though when it is released IE9 will at long last catch up significant ground on other browsers.