They haven't said it out right, but they have eluded that these will either be a new kind of "curse" that will work on bosses or that their modifying what curses bosses are immune to. But in any case these "Savant Curses" should be able to effect bosses.
Off-Topic:
Anyone know what type of damage DustII does?
According to the crafting planner:
DustII(Unholy/Acid/Acid): On-hit 2% chance, 400~514 damage, no save
Looking at the makeup of the weapon I would assume either Acid or Untyped. Acid would be awesome as it would give Earth Savant Sorcs a melee weapon to make, but I'm just being curious.