Immediately following the recent releases of Windows 8, Visual Studio 2012 and .NET 4.5, Microsoft has announced the new Blend for Visual Studio 2012. It is included with all versions of Visual Studio 2012, including Express.
Blend is a tool for designing user interfaces for HTML and XAML applications. This release is specifically for Windows Store applications targeting Windows 8. Support for visual HTML and CSS authoring is new to Blend for Visual Studio 2012, and the XAML Designer has been updated with features specific to Modern-UI (formerly "Metro"). According to the Expression Blend Team Blog, Blend’s JavaScript support has also improved:
It also is designed to handle app UX that makes heavy use of JavaScript to dynamically create and manipulate DOM elements. Blend constantly runs your code on the design surface, so that content generated by JavaScript can be displayed and edited accurately. Using Interactive Mode you can even interact with the app on the design surface and bring it into states that are not reachable via markup at all.
Microsoft is working on an updated version of Blend for Silverlight, WPF, and SketchFlow projects, which are only supported in Blend 4. That version is currently in developer preview for Visual Studio 2012.
Visual Studio 2012 with Blend is now available to those with a subscription from MSDN. Visual Studio 2012 Express can be downloaded for free from Microsoft.