Editor
I've been doing some work on the editor. Main reason is the lack of structure in the tracks you build (and the buggy user-interface). I thought of a structure that binds a few tracks together. This way you don't need to worry about the distance between two (or more) parallel tracks; the simulator will handle that. Also I'd like to build bigger stations; with tracks bound together (or grouped together if you will), it'll be easier to define platform placement etc.
Simulator
I've been looking at the DirectX SDK; I'd like to use 3d acceleration for the sim! That will allow both better looking graphics and more frames per seconds!