No. You didn't in Torchlight 1, either. Difficulty settings just change enemy damage, HP, aggression and range. You don't get more experience or better loot. The only difference to the reward system is that in the hardest difficulty you get less gold.
In the first game, experience was standard except in Easy where you leveled faster. They may be removing that for the sequel due to the online nature of the game.
Now Tiamat (one of the developers on Torchlight II) made a comment in one of his live streams that there may be differences between playing normally and on Hardcore, but difficulty won't impact that. Also, you will gain more experience and better loot on New Game+, but that's more a factor of the enemies being at a higher level.