To summarize the possible breakup of CN and CSX, simply look at this website: http://www.intermodalcanada.com/
(No sign of a .ca site)
As for NS on the D&H, running the 11R and 12R trains into Deerfield would certainly be possible. I see these trains each day and there is a hefty amount of Maine/New England traffic on board. If they had the train speeds, a Portland, ME to Linwood, NC train would be possible, but not probable to happen right now.
I would wonder if NS would try running oil trains over PAR again. CSX has access to Buckeye, as does CP, to move oil to Saint John, NB. The floodgates opened up again last week with 3 BNSF oil trains going over CN to Saint John. Pan Am has shed its eastern 58 miles from Waterworks east (With occasional run through service if needed or car storage at Old Town) in favor of a CMQ/NBSR routing. No doubt a BNSF-NS-PAR-CMQ-NBSR routing may work as the BNSF-CSX-PAR-NBSR routing was quite successful even given its operation challenges. From what I heard CSX got cold feet when PAR derailed more than a dozen tanks up in Mattawamkeag. The 85lb rail with poor tie and roadbed no doubt posed huge risk. I'm surprised CSX didn't run a geo train over this line before considering the service.
So in short, NS direct connection to PAS/PAR may lead to the return of oil trains. Also, NS direct connection to PAS may create a quasi NS-VRS-CMQ interchange gateway that I've heard some chatter about. Let's just say that Mr. Giles takeover of CMQ promised a 25MPH railroad and the work done this past summer and fall has done that not just to the east-west mainline, but also down into Vermont. Similarly VRS has both upgraded its tracks and raised clearances.... While I doubt oil trains will run up the Conn River, intermodal or other unit trains are certainly possibly bound for Saint John.
Sorry if some of you aren't up to speed on the far east railroads, but regionally the D&H transaction to NS will have a lot of ripples. From what I hear life is going to be quite different in a year or two up that way. I may have to switch over to the railroad side of intermodal operations in a few years if they work their way east.
This came out about 8 months or so ago that may be something of interest: http://www.panamrailways.com/PDF/offtotheraces.pdf