I wouldn't be surprised if the reason the conference was delayed was because they were making a shit ton of phone calls to their major retail partners to update pricing.
It means nVidia partnered with Microsoft to add a Raytracing API to DirectX. Whether raytracing will be a realistic option for developers with the next Xbox depends on the hardware, not the existence of this API.
2999 easy payments of 19.99 and one fucking complicated ass payment. We can't tell you which payment it is but one or these payments is gonna be a bitch.