As mentioned, it'll be just like MvC3, where 4 characters (including one or two VERY heavily played ones) are unlockable; any consoles there will simply have been prepared in advance by the tourney staff to have unlocked all the characters.
DLC should be allowed as well, if MvC3 is anything to go by the Evo standard will certainly allow DLC. Even if you don't buy the DLC character you're still able to fight against them and thus practice against them.
Kratos will be banned, for obvious reasons, but no one else will be imo.