The first platform preview of IE10 improves on IE9 by adding support for additional standards, such as CSS3 Gradients on background images and CSS3 Flexible Box Layout. Microsoft is promising a new platform preview approximately every 12 weeks. It's worth noting that with IE9, Microsoft promised an update every eight weeks, but this wasn't a strict schedule.
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. If Microsoft is saying the platform previews for IE10 will be spaced out an extra month apart, it would appear that IE10 will take more than a year to be released. We're thinking it will actually be less than that, but it's possible Microsoft will want to do additional testing with Windows 8, given that it is supporting ARM in addition to Intel and AMD platforms. In fact, in the demo today at MIX11, the IE10 platform preview was running on a Windows 8 build for ARM.
"The only native experience of HTML5 on the Web today is on Windows 7 with Internet Explorer 9," Dean Hachamovitch, corporate vice president of Internet Explorer, said in a statement. "With Internet Explorer 9, websites can take advantage of the power of modern hardware and a modern operating system and deliver experiences that were not possible a year ago. Internet Explorer 10 will push the boundaries of what developers can do on the Web even further."