Visual Studio will soon be upgraded to a new version, 2012. It will be more integrated into the new Windows 8 operating system, with all designing features available in Windows. For designers, it will be more easier to only use XAML as a language for the UI. XAML is also integrated into other designing products of Microsoft, especially in Expression Blend. Visual Studio’s IDE is also changing a lot. Now, you will have the same designer features for all supported languages, for example, C#, C++, VB. XAML designer is a new designing tool that should make it easier to synchronize Visual Studio with Expression Blend.

Source:
http://channel9.msdn.com/Events/BUILD/BUILD2011/TOOL-504T