NS got the former NYC/LS&MS line from Cleveland to Chicago. The PRR main you speak of is owned by CSX and a big part is leased to Rail America's Chicago, Fort Wayne, and Eastern from Gary, IN to Crestline, OH. From Gary to Hammond, the ex-PRR is still CSX but it's darn quiet. From Hammond to Chicago, it parallels the ex-NYC and was rationalized by PC so that the actual tracks were only on one of two parallel alignments (varies from place to place between ex-PRR and ex-NYC). That main is under NS control as part of their former NYC property. CSX primarily uses their ex-B&O line to access Chicago.
The new Acela: It's not Aveliable.