How to make Visual Studio's View Designer act like Express Blend's View Designer like the screenshot below?

Today when I opened a Demo Project, I found the VS was diferent from usual. So which setting can make the Document Outline window act like this?

My environment:

VS2010 SP1
Blend4 SP1
Win7

enter image description here

Solution

I found it out by myself. This because I have installed Visual Studio 11 Developer Preview. It changed the default program to open vs solution file. So the pic shown above is not vs10, it's vs11!