It wouldn't do much for small towns between the cities...unless, they expand the project and build a passenger train line that makes stops...but you would need a bump in population and economic growth(more jobs) in each city for that to happen.
The northeast is a good example of how trains have caused a massive growth in the area. New Jersey probably would be desolate if it were not for the New Jersey transit. New Jersey is essentially a big suburb for New York City and Philadelphia. Alot of people working in private corporations in any of those cities probably lives in New Jersey and takes NJT/MTA to go to new York and NJT/SEPTA for Philadelphia.