I predict this goes nowhere. Nashville has invested way too much in the convention center to let one developer overbuild (sobro, encore, and now sheet music) right next door. This kind of project casts a very long shadow over the neighborhood, and while the surface parking space in sobro needs to be utilized better, a project like this could end up being a much greater liability for the city.
On a side note, it sucks for the people at the Encore. Rather than having a series of buidings that step down in height from the river (as the originial sobro plan calls for), Tony is building the tallest (presumeably, most lucrative) buildings he can, and literally blotting out the sun for people who bought condos with great views.