If you've somehow run out of things to do in Torchlight 2, a hefty mod might be just the thing to brighten your spirits. The "Synergies" mod adds a new class, some new bosses, and a series of "raid like dungeon chains."
The mod (via PC Gamer) adds the "Necromancer" class, which combines aspects of the Emermage and Outlander, and adds a massive "Skull Barrage" attack. You can use this powerful ability to take on the end-game content, which Synergies makes more difficult with the addition of tougher bosses and overworld maps, with more armor sets as rewards.
Future versions of the mod plan to add a Paladin class, an "Incognito" armor set, more quests and world bosses, and another PVP dungeon. It's pretty ambitious, and might just hold you over until Runic adds official expansions.