We've just released an update for the C++ Tier 2 users.
A new Visual Studio 2013 lib has been added.
There's also a template_windows_2013 project for it.
If you've already installed the C++ libraries to your own folder it won't automatically copy the new files until the next major update.
For now you can copy them immediately with the Tools->Install Additional Files menu option in the IDE.
The AGK Team