Total electrification just isn't going to happen until there's a BIG shift in attitudes w.r.t. railroads in the US>
That said, there's a good argument for extending some Amtrak wiring.
As for doublestacks? Just put the wire higher. Nothing magical about the height.
Clean coal isn't going to happen. Utilities don't even want it, now. Plant cost is approaching that of a nuke, operating costs are higher, siting is almost as bad, there's almost as much liability. And a 'clean coal' plant still depends on coal deliveries every day or two. And the utilities are NOT happy with the way the RRs are treating them.
Put it this way: utilities are canceling their plans for 'clean coal' plants, and submitting applications to the NRC for nukes - there's licenses for 5 units in now, and another 15 or 20 expected by the end of next year. This is minus Watts Bar #2, which the TVA says they will start work on (again)( this January.
Carbon sequestering is a big question mark, the newer emissions controls are adding complexity and costs, and may not be enough, anyway. On the flip side, today's new nuke designs are simpler, safer, make less waste, and cost less.
If the long term shift towards nuke continues, you'll see RR electrification for two reasons:
* RRs will lose coal traffic. Coal's a captive customer, i.e. a money machine. They'll have to start grabbing traffic from trucks, which means a huger increase in speed and performance.
* Cheap electricity and high oil prices (90 a barrel's a certainty, 100's easily possible) will make electrification look attractive.
Looking into a 'crystal ball', I'll go out on a limb and predict the first new freight electrification in the US will be in the southeastern part of the country.