I'm hoping for the 3C+D to make fruition as well. Not only with me being an Amtrak railfanner in central Ohio, but I agree with the above that it would open up the corridor and allow a good flow of traffic through Ohio from places in NKY as well.
It would be cool to see Cincinnati Union Terminal serve another train rather than just the Cardinal, a midpoint here in Columbus for passenger rail and a point southward from Cleveland. Plus, Dayton could also benefit from a station being there as well.
I know that the 3C+D is still a long ways away from possibly happening, but it's good to dream (and yes, I have dreamed of the different rolling stock it would have too, hehe).