Earlier this year, I wrote a Windows Phone app. I had to register for the Windows Phone store (and pay $19) so that others could download my app. Later in the year I wrote a Windows 8 app and registered for the Windows 8 store (for an extra $49).
Registering for these stores was not a huge chore and the cost was still cheaper than the iOS store. But this process just became much simpler and much cheaper. Microsoft announced this week that developers can register for both the Windows store and the Windows Phone store for a single annual fee of $19.
If you are already registered for one of these stores, you will automatically have access to the other; and, if you've registered for both (like me), you receive an additional year for free.
Full details of these changes can be found at http://blogs.windows.com/windows/b/appbuilder/archive/2013/11/06/unifying-developer-registration-windows-and-windows-phone.aspx
This is good news for people like me who like processes to be simple and fees to be low. It removes much of the friction of publishing an app.