Some resources of interest for .NET Framework 4.5 developers are as follows:
The Visual Studio 2012 launch website http://visualstudiolaunch.com/.
The .NET Framework blog http://blogs.msdn.com/b/dotnet/.
The .NET Framework's Twitter handle https://twitter.com/dotnet.
The Developer Tools Blogs http://blogs.msdn.com/b/developer-tools/.
The Visual Studio Blogs http://blogs.msdn.com/b/visualstudio/.
The Microsoft's Expression Blend team blog http://blendinsider.com/.
The Visual Studio Developer Center http://msdn.microsoft.com/visualstudio/.
The Visual Studio official website http://www.microsoft.com/visualstudio.
The Visual Studio resources website http://msdn.microsoft.com/vstudio.
Microsoft Developer Network's What's New in the .NET Framework 4.5 http://msdn.microsoft.com/en-us/library/ms171868.aspx.
Microsoft's Virtual Academy http://www.microsoftvirtualacademy.com/.
Microsoft's patterns and practices site http://pnp.azurewebsites.net/en-us/.
Codeproject search for .NET 4.5 http://www.codeproject.com/search.aspx?q=.net+4.5&x=-1287&y=-147&sbo=kw.
Channel 9 http://channel9.msdn.com/.
The Microsoft Developer Network home website http://msdn.microsoft.com/.
There is a really cool end-to-end sample, from being a web backend to a Windows Store app, that Layla Driscoll showcased at TechEd North America and TechEd Europe. It's called What's New in the .NET Framework 4.5 and can be found at http://code.msdn.microsoft.com/Whats-New-in-the-NET-e8d7545c.