A quick Google search confirmed this:
Microsoft revealed this week that Internet Explorer 10 Metro will not support browser based plug-ins.Full Story Here
“For the web to move forward and for consumers to get the most out of touch-first browsing, the Metro style browser in Windows 8 is as HTML5-only as possible, and plug-in free,” revealed Internet Explorer chief Dean Hachamovitch, in a blog post earlier this week. Microsoft is removing the ability to use plug-ins on the Metro style IE version of Windows 8 to improve security, reliability and battery life for end users. “Plug-ins were important early on in the web’s history,” admits Hachamovitch. “The web has come a long way since then with HTML5.”
Although I do find it hard to believe there will be no plug-in or add on capability in Internet Explorer. It looks like Flash really is gonna be dead soon. The times are changing fast.