See how designers and developers can work together creating rich SharePoint applications in my MSDN article:
Data-Bound Design: Create a Silverlight 4 Web Part for SharePoint 2010
One of the most challenging aspects to SharePoint development is the sheer number of choices. Then add on top of that the need for great design and usability. These design and usability aspects are often not a developers strong skill. So how do you bring designers into the mix and allow them to create great designs that work well in SharePoint? The answer is to use Silverlight and Expression Blend. Using Expression Blend’s sample data functionality you are able to generate some sample data from your SharePoint site and hand that off to a designer. The designer, without knowing anything about SharePoint, can take that sample data and create a great application. Then the designer can hand the app to a developer using Visual Studio who can hook it up to live SharePoint data, with only a couple of lines of code.