My fear is that XNA has reached the end of the road. To keep up with the latest technology a shift to another game framework might be needed. We have many games in a large codebase, all based on XNA. My question is, how much work would it be to migrate to SharpDX and are there other possibilities?

Our code base mainly uses basic 3D rendering and the SpriteBatch, no fancy shader stuff.

Update:

I should have mentioned we only use 2.5D, we have a simple engine that builds textured quads to render text and animated sprites. Also for sound we use XACT (what else..) with some effects.