CATNAP,
The locomotives you have mentioned Dash8-40B, GP60, SD40-2 seem to be too modern for 3 rail crowd.
One of the comments about York was that "most of the people at the meet will be dead in 10 -15 years", by the time the Manufacturers get on the ball with "modern" (1970 & 1980s Diesels) it will be too Late as Most of the Modelers have already Left O gauge for HO.