I'm not saying that the F69s don't deserve to be preserved, but I have to question a few things mentioned by BN7151. I think that there would have been SD--MAC freight locomotives without the F69s; something else would have been the first prototype ACs.
And did they really rack up "millions of miles" in Amtrak revenue service? I seem to recall that they bounced around between EMD and Amtrak, lots of little bugs, lots of fine tuning, and that they were retired somewhat early, although that may be because they were a prototype, in a sea of F40s. Later, they got cleaned up and used to pull the X2000 around on non-electrified track, when the X2000 was on tour. (Or was it the ICE? Too long ago-)
Again, not to take anything away from them- And I have to re-read up on Jay Street 4, but I still feel (as do many others, I'm sure) that CNJ 1000 was the most influential North American diesel-electric.