My team at Microsoft did a day long webcast on WinRT app development. Please find the video recordings below.

Introduction to WinRT app development – http://sdrv.ms/RTp3SL

Building WinRT apps using C#/XAML – http://sdrv.ms/RTpc8X

Building WinRT apps using JS/HTML – Part 1 – http://sdrv.ms/Pj2SD8

Building WinRT apps using JS/HTML – Part 2 (Contracts / Tiles / Notifications) – ttp://sdrv.ms/RToXL5

Windows 8 Process lifecycle Management – http://sdrv.ms/Pj2JiQ

<cross posted> http://ramaprasanna.wordpress.com/2012/08/20/video-tutorials-on-winrt-app-development/