I know there was a lot of discussions about VS 2012 express. Those were about MS does not allow to develop desktop applications with it freely, aside of metro ones. Even MS said to developers to download VS 2010 Express if they want to develop desktop application.
Has anything changed with VS 2013 release?
On
Microsoft Launches Free, Unrestricted Version Of Visual Studio For Small Teams
http://techcrunch.com/2014/11/12/microsoft-makes-visual-studio-free-for-small-teams/
Yes you can create Windows Desktop (WPF, WinForms and Win32) apps with C++, V# or VB.NET using VS 2013 Express for Windows Desktop.
VS 2013 for Windows Desktop
Here is a link to the Visual Studio Licensing document. Not sure why it does not state VS 2013 but it does state VS 2012 for Windows Desktop, but it does say you can use them to develop production applications.
VS 2013 Licensing
Visual Studio Express 2013 Products
A number of free development tools are also available, including Visual Studio Express 2013 for Windows 8, Visual Studio Express 2012 for Web, Visual Studio Express 2012 for Windows Desktop. These tools provide a subset of the functionality available in Visual Studio Professional 2012 and are specific to writing applications targeting these platforms. Each of these Visual Studio Express 2012 products is licensed per user and subject to the use terms included with the product. Visual Studio Express can be used to build production applications.
No idea why MS would change this from VS 2012 to VS 2013.