I just got it from Impulse, along with Railroad Tycoon II and 3 from Steam. Impulse purchases. Playing all three, there are features from each that I like - and do not like. Unfortunately, I can't merge them all.
Since this is a speculative question, I'd imagine it will be a long time before seeing anything like the level of detail and complexity of RRT2 or 3. Or the original for that matter. This opinion is supported by the fact that Sid Meier's Railroads!, the latest in the series, took a very different approach and stepped a bit away from modeling both railroads along with the associated industries, financial market (stocks/bonds) and the game maps themselves (being more abstract than in the earlier games).
That said, Railroads! isn't a complete waste - but it does try really hard to crash itself if you make changes to certain options in ways that you would think would be 'ok' but for whatever reason the game can't manage the change. This is complicated by the mods that the user community has created - and it's been a labor of love for some fan or modding sites related to Railroads! to try to do what they (the modders) can to ensure that their mods can play without crashing someone's game.
So, to answer your questions.. I think it's really up to the fans/modders to produce the new content -which should have been very easy to do with data stored in .XML files. Unfortunately, the stability issues fight nearly every effort made to customize the game. As for a game patch, I just don't see an official patch happening. However, there are (or were) fans of RRT3 that managed to cobble together an actual binary patch (unofficial) for RRT3. Perhaps something similar will happen in the future for Railroads!
Railroads could be great if you can make the maps scale larger, the trains/cities/industries scale downward a bit so they 'look' right in the world, add new industries and cargos, new trains that work with all maps/mods instead of having to re-create everything for each mod (to help minimize stability issues). It really should be easy to do - but it's not atm.
