I am building a desktop application using VS2010 C#. I plan to design and implement my own ribbon and redesign other UI controls graphically. Would Expression Studio/Blend be useful for my purpose? I have not used the software and from the web it says it's mainly for Web.
Expression Web is for web design. Expression Blend is for Windows Presentation Foundation and Silverlight. If you want to use Windows Forms then you have to either do it all by hand or use the Visual Studio 2010 designer but if you want to use WPF then Blend is the way to go.