See intro blogpost here.
Over the last few months several other people have been writing blog posts covering the transition from WPF/Silverlight/WP7 to WinRT. Below are some of the ones I’ve stumbled upon.
Colin Eberhardt - XAMLFinance - A Cross-platform WPF, Silverlight and WP7 Application
An app that reuses code across 3 different XAML platforms and compiles for all of them. A great example that this can be accomplished. Also make sure to check out Colin’s blog for more WinRT goodness.
Jeffrey Richter - Core .NET Type usable from a Metro Styl Application
A list of the “standard” .NET types that are available in WinRT as well.
Andy’s blog - Physics Games: Multi-targeting Windows 8 and Windows Phone 7
Andy goes through building a physics-based game for both Windows 8 and Windows Phone 7. Also check out his Physics Helper library for WinRT.
Tim Greenfield - “WinRT Genome Project”
Visual comparison of how much overlay Silverlight 5 and WinRT has.
Tim Greenfield - Silverlight 5 vs. WinRT comparison
A follow-up to the link above with a comparison of namespaces, members, types and differences between SL5 and WinRT. This is an amazing list if you want to get into the details when reusing code between the two frameworks. Pontus Wittenmarks’s - 10 tips about porting Silverlight apps to WinRT/Metro style apps (Part 1)
A quick list of of tips when porting from Silverlight to WinRT.
Petzold Book Blog - Windows 8 Dependency Property Strangeness
Talks about some of the issues with Dependency Properties in Windows 8. I already briefly touched on this, but this goes a lot more in-depth.
If I find more, I’ll add them here, or feel free to mention any other good resources in the comments below.