If you're consistently playing with a Barbarian who is buffing your resistances, in addition to being your meat shield, then your gearing strategy should be similar to pre-patch with more focus on damage output (your health and resists are reasonable and more than sufficient to kill up to Azmodan and beyond, depending on your skill level). Your focus on damage output should not totally neglect Increased Attack Speed as it is still a good stat, but it shouldn't focus on it as your primary stat. Remember that the mechanic itself wasn't nerfed, only the value of IAS on items.
Stacking intellect is always good as it has additional effects (gaining more resists). A balanced combination of Critical Hit Chance and Critical Hit Damage % will give you a noticeable increase to DPS as well. The largest single factor in damage output for casters/ranged in general is still the damage range on weapons.
You say that your damage is 21K while buffed - are you using both Force Weapon and Familiar, or is this value with just one of them? 21K damage after being buffed by either of these abilities is low - aim for at least 25K+ unbuffed to have an easier time of killing enemies.