It would be nice to have some streamliners, specifically the J class locomotives from the Norfolk and Western Railway. There's already the SP "Daylight" GS-4's, and the union pacific FEF-3. So it would be nice considering the fact that I would want to race one against an NS train.
The possibility of the N&W J, (as well as other N&W steamers) have been brought up here before, but it's highly unlikely since the J's design has been trademarked by N&W 611's care takers.