http://www.microsoft.com/games/trainsimulator/ 

Redmond, WA, January 19, 2007 – Following the successful release of Microsoft Flight Simulator X, the Aces Studio is using the same technology to develop a new version of Microsoft Train Simulator. Unrelated to our previous Train Simulator development efforts, this version will be an all-new product built on the Flight Simulator X platform, the culmination of 25 years of product development and technology.

It’s too early to discuss the details of this product, but we look forward to sharing more information later this year.