Check out the Cape Chignecto Coastal Trail. Its awesome. I backpacked it last summer. It takes three days and its about 35 miles, a loop trail that circumnavigates the Bay of Fundy for about 20 miles. The park is new and the trails and campsites are extremely well designed.
http://www.outdoorns.com/features/chignectopark.htm
I actually drove to NS last year, because at that time, the Scotia Prince lines out of Portland were closed due to toxic mold in the terminal. Not sure if that's changed...
Sabrina