The Naruto Shippuden: Ultimate Ninja Storm 2 demo at Gamescom, the European trade fair that recently just took place, featured 18 playable characters. In the character selection screen, however, were a total of 42 character slots.
Currently 39 characters have been confirmed. Who are the other three? While it is not confirmed, we would bank on Tobi/Madara and Konohamaru to be number 40 and 41. But as for the 42nd character, well, looks like only time will tell!