If you were to hypothetically enchant all the items on your main character once you start up the expansion, what rolls would you switch out or improve.

Don't forget this rule about split stats:

I don't have a specific list available, but items with split stats enchant normally. Say you have a split stat of +97 Str/+64 Vit (again considering I am pulling all these numbers out of nowhere - they aren't final in any regard). When you choose to reroll that stat, both the Strength and Vitality will be replaced by one of the newly available stats (like 197 Strength, for example).

So if you don't want to decrease or lose your Int and Vitality on an item then you should leave your split stat roll alone.

Split rolls can be the following combinations:
Dex/Int, Dex/Str, Int/Str, Dex/Vit, Int/Vit and Str/Vit



Here is what I would do with the items that you can see on my female life regen wizard:
http://us.battle.net/d3/en/profile/mentok1982-1212/hero/3469482

Tal Rasha's Guise of Wisdom: Has Intel/Vitality split stat.
Increase the life regen roll from 328 life per second to 342 life per second.

Vile Ward: Has Intel/Vitality split stat.
I don't think I can improve the intel or vitality without losing some intel or vit.

Mortal Choker rare amulet:
Replace the int roll with 9% AS which will make it a quad ammy I can use on any class.

Zunimassa's Marrow:
Increase the AR roll from 73 to 80. The Int and Vit rolls are really high already.

Highlander's Hold rare gloves: Possible Int/Dex, Dex/Vit or Int/Vit split stat.
Replace the Dex or Vit with 9% AS or 80 AR depending on which is not a split stat.

Brutal Shackles crafted rare bracers:
Replace the 97 Dex with 342 life regen.

The Witching Hour: Has Intel/Vitality split stat.
Might replace the 218 Armor with AR or Life %.

The Treasure rare ring:
Change 40 Fire Resist to AS, or AR.

Hellfire ring:
Change the 40 Physical Resistance to 9% attack speed.

Depth Diggers: Has Intel/Vitality split stat.
Increase the life regen from 337 life per second to 342 life per second.

Zunimassa's Trail:
Increase the life regen from 334 life per second to 342 life per second.

Chantodo's Will:
Increase the 41% damage to 50% or if that is not allowed, increase the intel.

Chantodo's Force:
Increase the life regen from 97 life per second to 342 life per second.

Interesting question. Assuming my gear doesn't become instantly worthless once I start leveling my DH past 60:

Scavenger's Burden Amulet:
Replace the 26% better chance of finding magic items with IAS or AR

Undaunted Traps Gloves:
Replace the +34 poison resistance with IAS

The Witching Hour Belt:
Probably try to re-roll the low Dex (it's only at +27)

Those are the only things I can see offhand that I would try to change about my currently equipped gear. I have a good Mempo in my stash that I might try to get CC on, though unsure if it's worth breaking up the split high Dex/Vit roll it has...

I read that there are now primary and secondary rolls (forgot if these were the terms), and usually the defense stats are secondary ones. So for instance, you wouldn't be able to reroll a fire resist on a ring for IAS or crit.