Preheat the oven to 400°F. Slice the baguette, and place the slices in a single layer on a baking sheet. Toast 15 minutes until slightly browned and crisp.
In a small saucepan, place ½ cup dried Montmorency cherries, ½ cup water, and 1 tablespoon balsamic vinegar. Bring to a strong simmer and simmer until the liquid is reduced by one half, about 7 minutes. Allow to cool for 5 minutes.
Thinly slice the sage leaves. To serve, spread goat cheese on top of the crostini; top with cherries and a bit of sage.