We don't even have a beta of Windows 8 yet! 🙂
So in other words we have nothing to announce at this point, and no promises when or even if this would be released. It's simply just way too early and frankly I don't think anyone knows (the dev preview is too buggy to do any serious work with anyhow).
Since Windows 8 metro apps can also be built with HTML and JavaScript, you can already do this today. There are some minor issues with touch support, but as IE10 matures, the JS API will also add support for touch.