Expression Studio Web Professional combines Expression Web with Expression Design and Expression Encoder to give you a full graphic, video, and web design suite.  This suite combines exactly what most web designers need to create great sites with strong support for languages like PHP, HTML, CSS, and ASP.Net.  

Expression Studio Ultimate combines Expression Web with Expression Design, Expression Blend, Encoder Pro, and SketchFlow to give you a full graphic, video, and web design suite.  Expression Studio Ultimate is perfect for the developer who works mostly on ASP.Net projects. There is extensive support for ASP.Net and Silverlight.