This article is about "improvement" in Visual Studio 2012 unit testing. I think it doesn't happen very often to have an upgrade which makes the functionality worse than the previous version. In the case of the new Test Explorer window we can even talk about removing previously available functionality because the new window is mostly useless for any bigger solution. Until Microsoft improves the window we are not away from the testing experience known before Visual Studio 2008 when we didn't have any built in support for unit testing and we had to use third party plugins or external test runners.
I wanted to write this article immediately after I tried the new Test Explorer in Visual Studio 2012 Ultimate RC but I still believed that Microsoft will improve it before launching Visual Studio 2012 especially when complains to the new Test Explorer appeared long time before RC. Unfortunately Visual Studio 2012 RTW was released with the same Test Explorer window and there is also no update available yet. Test Explorer window should be hopefully improved this fall. There is also related request on Visual Studio User Voice with few other suggestions for improvements in comments.
The rest of the article describes what is wrong with the new window and compares the functionality with Visual Studio 2010 and Resharper 7.