Do you suppose that in the future some group will organize with the goal of preserving some AC-4400 diesel? It may be significant for some reason or another or for no reason at all other than it is what they used to use. Do you think that modern diesel power will have a historical signifigance or romanitic nostalgia that will cause groups of unrelated men (and women) to throw money, labor, and hours of their lives at it?
Already there are groups that love nothing else other than diesel power. As they age, it is probable that they will long for that "old" power to be seen and run again. Some will form groups and do all they can to see this goal to fuition while others will only loock back at old photgraphs and video footage. Inevitabley, what is now modern will become old; this includes both the equipment and their fans.
Perhaps those diesel fans should look towards becoming involved with steam operators of today. While steam may not be their fancy, these groups are established and may have the resources and desire to someday rescue old, tired high-horsepower diesel engines as part of their rail collection. What works now may work in the future both in terms of operation and policy as well as organization. Furthermore, those that are involved may gain an opportunity to become elected to a post within the organization that can influence and steer the group into desireable directions.
Of course, I haven't seen a railroad retire a modern locomotive to a community park in, oh, ever. Railroads don't have that community backing like they once had. Mostly, they are seldom seen or noticed and are simply two steel bands causing traffic headaches as they bisect the local community. Maybe the railroads will simply take the scrap value and let be at that.
Whatever happens to modern locomotive power, there will surely be someone who will miss them. Someone will lement over the fact that they did not or could not save at least one. For proof, look at the old NYC J-class 4-6-0s that are long gone. I'd like to have seen one. Alas, they are gone. So, whatever your likes or dislikes, get involved now and help preserve our rail heritage. Afterall, even yesterday is just a memory.