In a recent interview, Magicka 2 developer, Pisces Interactive, mentioned that while DirectX 12 is going to be a big improvement, they expect the next-gen OpenGL Vulkan might even be even more promising than DX12:
They have a very positive outlook on the new API that will become available along with Windows 10; at the same time, though, they said that Vulkan might be even better.
DX12 is a big improvement over DX11, it enables games to move to the next generation of graphics. But we’re also eagerly awaiting the official release of OpenGL Vulkan, which might even be better than DX12. Currently we are only experimenting with the API’s but we will of course support them eventually.