I too was disappointed about the death of XNA. I am working on a rather large project that used XNA, and since finding out XNA was getting the axe, I have switched over to SharpDX. I actually prefer working with a lower level interface than XNA. While XNA is nice and convenient I think overall I just prefer the low level API access. You can still use the parts of the XNA API that are timeless, such as the 3D vector math library, but as for the rendering engine, SharpDX provides the same functionality with more flexibility.
Or you could just switch to MonoGame, of course.