Currently items are all pretty similar. Each new expansions just added a little more H/s or M/s, a little extra DPS etc. It would be great if items had a big overhaul and some cool new features were added to them. Some ideas are as follows:

1. More damage procs.
2. Non damage spells procs. Rage, Evade, Haste, Stone Skin etc
3. Heal or Mana procs. Like drinking a pot.
4. Spell effects you can't get from skills

All these would have low chances of firing, with the chance directly related to the rarity.

Added to this it would be good if when you clicked on an item you got a new window pop up over the right side of the inventory window so more detailed information could be shown. There are already a number of items that have more features than can be shown in the current interface.