Kendor you are correct. The direction of the arrow indicates the reactants going toward products. In this case you are dissociating the water into the component gases. This direction is not spontaneous. Most often I've seen this reaction named in the process of electroysis of water. It requires energy(work) to make it happen. (The formation of water from the elements releases energy in the form of heat).
Clarebear is close.. To balance the equation for normal form of 1 oxygen molecule (2 atoms) and 2 hydrogen molecules (4 atoms) we need to break apart 2 water molecules.