Steven Sinofsky posted a new blog entry about the new Metro style Internet Explorer included in Windows 8

Running Metro style IE plug-in free improves battery life as well as security, reliability, and privacy for consumers. Plug-ins were important early on in the web’s history. But the web has come a long way since then with HTML5. Providing compatibility with legacy plug-in technologies would detract from, rather than improve, the consumer experience of browsing in the Metro style UI.

The reality today is that sites are already rapidly engineering for a plug-in free experience. Google, for example, recently launched their HTML5 YouTube site for phones. A previous IE blog post discussed how plug-in free sites are becoming more mainstream, and what sites can do to run plug-in free. We examined the use of plug-ins across the top 97,000 sites world-wide, a corpus which includes local sites outside the US in significant depth. Many of the 62% of these sites that currently use Adobe Flash already fall back to HTML5 video in the absence of plug-in support. When serving ads in the absence of plug-ins, most sites already perform the equivalent of this fallback, showing that this approach is practical and scalable. There’s a steep drop-off in plug-in usage after Flash, with one control used on 2% of sites and a small collection of controls used on between 0.5% and 0.75% of sites.

  Windows 8: Metro style browsing and plug-in free HTML5