If the New Haven hadn't been blocked from outright purchasing the B&M and Maine Central (and doing so made it profitable), we could have had ep-3's running into Boston South by the 1930's, with electrically powered commuter trains on the old colony branches looping on a pocket track under South station. Probably electric service out to Providence to. Maybe even some kind of NSRL (even one at surface level). Of course, a New Haven that big could mean all sorts of butterflies for New England politics in the teens and twenties. I sense a TL coming on.
Of course, there's always the "Ooh, if the Milwaukee Road had held onto the wires for just a little bit longer they would have been in a great position to profit from the oil crisis". In order to hold onto it for any longer, they'd need to modernize their system and close the gap out west; like
@Mike Stearns said, a good make-work project during the depression perhaps.
If the oil crisis lasts longer and someone radical, I dunno, George McGovern perhaps (
@Yes), is in charge of the white house, he could try to give railroads money to do the electrification projects they weren't able to make profitable themselves. I know the Santa Fe had talked about electrifying their entire main line during this time; that'd be a sight to see.