There doesn't seem to be a clean way to set this directly (but might be worth a feature request to add that), however the title is just a text artist, so you can reach in and change it.
#ax = plt.gca()
ttl = ax.title
ttl.set_position([.5, 1.05])
#plt.draw()
should do the trick. Tune the 1.05 to your liking.