Will you need a 4K TV to take full advantage of the Project Scorpio? According to this guy you won't.
Lastly, games that sport True 4K assets will also enjoy graphics enhancements on 1080p displays, thanks to the console's supersampling technology. There are many games on Xbox One that sacrifice anti-aliasing quality for performance in other areas, resulting in models with jagged edges. Anti-aliasing gives objects the appearance of smoother edges, at the cost of system resources.