For a while it looked like the traditional caster staffs were getting a buff, not huge but a small one, both in random loot and in TF. (2 handeds in general there as well) however with the new loot and with GS this seems to have fallen by the wayside leaving us with the 2 single handed weapons again though this includes orbs.
While ideally I would like to see the caster staff as marginally more powerful, perhaps a better solution is to allow an off hand item to be equipped for any 2 handed item with only the physical effects of the main hand weapon (physical attacks etc) taking effect, but the passive ones continuing to work.