> How do I know for sure? Well have you heard of Intel developing a new graphics api > for Haswell? I haven't, but maybe I missed it. But what kind of dev would support > something new and exclusive to it rather than direct3d/opengl that everything else > has supported for years.
The private API interacts with and extends D3D, like NVAPI and ATI's Eyefinity API have for years. It's sort of like GL vendor extensions except there's no standardized framework.