I bet that TPCi will throw us a curveball and have the 2 theme decks have 3 different energies rather than the usual 2. The Japanese half decks with Hydrieghon and Garchpmp (whatever) has 3 different energies, so I think the Dragons Exalted theme decks will also have 3. I think the energy types in the Japanese version and the international version will be different. 3 headed dude's deck will still have Psychic and Darkness, and Sharkman will have Water and Fighting for sure, but the change comes in the third energy type. So to figure this out, look at what energy cards are used in the Japanese half decks. Take away the energies that aren't used to powerup Hydrgon's and Garchmp's attack. Look at the blend energies of the respective decks, and put in the one energy type that isn't used from that blend energy.
The result is that one deck contains Fire, Psychic, and Darkness, while the other one contains Water, Fighting, and Metal. That is what I think of what energy types will be in the theme decks.