These are the folks who made the MSTS Train Sim. I just dropped into my local GameStop and it was there so I nabbed it, and surprised me to see it.
I thought it was only going to be a european release, but it has a few American routes and equipment, so I guess Kujo changed their mind about what they were to do.
Its supposed to be techniquely quite above the MSTS Train Sim with higher detail, uses the Physx Physics engine like new games use with higher detail. If you plan to run this game expect to have nearly today's systems with the newer vidcards.
MS is working on it seems on MSTS 2 using their flight sim engine.
RS has an editor as well and custom content is possble. I havent installed it yet because I have a little gamer system revamping to do.
I have no clue if it would accept MSTS content or not.