Managed code will never be as fast as close to the metal native. Managed code lives because of abstraction concepts, and abstraction equals cost.
right. But next years tick/tock of the processor will give us hundreds of millions of more instructions per second, erasing whatever gap there is with the native app. And of course there is many core which is predicted to give apps multiples of CPU resources. I understand hand held devices have power constraints. But is it predicted that 5 years from now a WinRT native stack will be needed compared to a device that runs mostly managed apps?