No doubt the spare parts and replacement engine market will continue. There may be some demand for marine service, but many US operators are actually removing the EMD engines out of their tugs replacing them with T4 Cat, Cummins or other models due to pressure to get rid of their "dirty" diesels. Obviously not all countries have the same strict standards, but I believe much of Europe does.

There has been a suprising market in the marine industry for older designs. The last I knew the GE FDL was still being supplied to the marine market (under a different designation), the Alco 251 is still popular and in production (now built by Fairbanks-Morse), so there may still be a demand for the EMD 645 and 710.