Microsoft released the 4th platform preview of IE9, According to Dean Hachamovitch, "this release demonstrates the potential advantages of fully hardware accelerated HTML 5 graphics, performance improvements on industry standard tests. IE 9 Platform Preview 3 received a score of 88/100 on the Acid 3 test while PP4 scores 95/100. The remaining points that are missing involve SVG fonts and animations currently being transitioned."
"In preparation for upcoming beta scheduled for September, Microsoft is asking Web Developers to begin coding their sites according to web standards rather than testing for IE versions."
Hachamovitch stated that the IE 9 platform is nearly complete and therefore, ready to be tested publicly.
Download: IE8 developers preview