That's the question I was asking after installing Microsoft Expression Blend 3. It appears that two DLL references are missing - or at least misplaced.
They are located at C:\Program Files\Microsoft SDKs\Expression\Blend 3\Interactivity\Libraries.
In my case (64bit) it was C:\Program Files(x86)\... as shown in the image that follows.
Add the references and all will be happy.
Below you can see that after adding references our view will display. Note Expression Blend 3 offers 140 controls! 
Tags:
expression blend,
wpf,
silverlight,
headbanger
Categories:
WPF