Microsoft just released Expression Blend 3 + SketchFlow RC.

This time we get SketchFlow !

You might download Microsoft Expression Blend 3 + SketchFlow RC from this page.

Overview

Expression Blend 3 + SketchFlow is a visual tool for designing and prototyping desktop and web applications. You build an application by drawing shapes, drawing controls such as buttons and list boxes, making the pieces of your application respond to mouse clicks and other user input, and styling everything to look uniquely your own.