Microsoft has released the second platform preview of Internet Explorer 10. You can download it now directly from the Microsoft Download Center: Windows Internet Explorer Platform Preview. Until Windows 8 is released, Windows 7 32-bit or Windows 7 64-bit is required to install and use IE10.
Internet Explorer 10 Platform Preview 2 adds support for several new technologies like CSS3 Positioned Floats, HTML5 Drag-drop, File Reader API, Media Query Listeners, and initial support for HTML5 Forms. HTML5 Application performance has been improved across the board, as well as the ability to deliver better performance with more efficient use of battery life with new technologies like Web Workers with Channel Messaging, Async script support, and others. Web application security has been improved using the same markup with support for HTML5 Sandbox for iframe isolation.
IE10 is expected to be the version of Internet Explorer that comes with Windows 8, which should ship in 2012. Microsoft released the first platform preview of IE9 on March 16, 2010 and then released the final version on March 14, 2011. IE10 should thus be released in 2012, but we're hoping it to take less time to develop than IE9. If a rumor that says Windows 8 will RTM in April 2012 proves true, this could indeed come to pass.
Microsoft is promising a new platform preview approximately every 12 weeks. IE10 PP1 was released on April 12, 2011, which is about 11 weeks ago. With IE9, Microsoft promised an update every eight weeks, but this wasn't a strict schedule.