When Microsoft announced that they had no plans on integrating plugin support on IE10 Metro, the whole world looked in shock. Since many popular websites and widgets still use flash today, IE would be again missing out on something big. Today, it seems the company has changed it's mind, and plans on including Adobe Flash with Windows 8.
According to an unofficial Microsoft source, Windows 8 may include flash support after all. Now, this does not mean plugin support. According to the source, Adobe shared the source code with Microsoft so they could bake it right into Internet Explorer Metro. This is good news, it means you'll be able to watch YouTube without switching to HTML 5! As it is not from official Microsoft representatives, we advise you to take what you read with the knowing that it could be false. Source: WinUnleaked Forums