First, we're upping the damage of many skills with longer cooldowns in 1.0.4. Across all classes, if I can only hit a button once every so often, it needs to dole out some significant damage to justify the spot on my bar. While some skills, like Archon and Wrath of the Berserker, are significant enough to make the cut, there are a lot of skills that need DPS improvements to make their cooldowns worthwhile.
Not from the DH preview, but I would bet Rain of Vengeance will be getting a big boost. Stampede is already really awesome in dealing with elite packs. Can't wait to see.