The Chapelon engines sound cool. I like the look of his Pacifics. What I really want is the ATSF 4-8-4 #3751, UP 4-12-2, and some remakes (Big Boy, Challenger, SP GS4, etc.).
It'd definitely be nice to have some high quality remakes of existing American steam loco DLC's. ESPECIALLY the G-Trax ones. They've aged as well as a mayfly does. Same goes for their freeware lightweights on RWA. If possible, it'd be nice if said remakes were advanced as well, but that would add time to getting it out, so finding the right developer could be tricky. Smokebox is only one person, so it'd be nice if more then one person could do it, so as to lighten the individual work load.