New features in Expression Blend 4
Silverlight 4.0:
1. Silverlight for Windows Phone 7
2. PathListBox
3. ListBoxItem layout states
4. Shapes
5. New behaviors:
6. Conditional behaviors
7. Design-time resource dictionaries
WPF 4.0:
1. Visual state manager-aware controls
2. Easing functionality for animations
Visual Studio 2010 interoperability
SketchFlow:
1. Player improvements
2. Authoring improvements
Support for M-V-VM templates
Data store:
1. Design-time improvement
2. CLR type sample data
Source: Expression Blend 4 unleashed