Mr. Raper said they planned on shipping about 700 cars/year. CN says they will put the rails back if there is sufficient business to justify it.
Miramichi Lumber Products was known as Newcastle Lumber until a few years ago, when the family-owned business went into receivership. It is back in operation with a new name and new equipment.
I don't think the rails will ever go back. The northern line is in dire danger since CN filed for abandonment in August last year and nothing has come up since then to indicate they will change their minds. There is simply not enough traffic to justify CN making the investment to repair the line's many faults. The various levels of government, private business, and community leaders need to work together to get more industries using the rails to make the business case for retaining the line. Organizations like this are good but there needs to be more... much more.

I remember seeing New Brunswick East Coast Railway trains coming down to the port many times to spot boxcars, and even to switch the Irving propane facility there when it still had rail service. I have a note that I saw an SD40 / C-424 combination coming away from the port on February 13, 2001 but in general I only saw RS-18s there. Of course, the above photo is an exception as the second unit after NBEC 1867 is NBEC 4230.
In January 2004 it was a pair of RS-18s (NBEC 1814 and 1821) working the port. Note the BC Rail boxcars. There was a shift around this time from a dog's breakfast of boxcar roadmarks to more uniform CN and BC Rail boxcars in northern New Brunswick.

The last time I saw a train at the Port was in the evening of July 18, 2006 when NBEC 1854 and NBEC 1816 were working. Clearly this was shortly before the end of rail service if CN says the line has not had customers in seven years.

Notice how my camera quality improves with each picture! ;)