I wouldn't mind a separate magic based damage staff, which changes the healing abilities while slotted (similar to destruction staff). They did a lot of the sun stuff with templar, but it could easily be expanded on as another staff option using the restoration line as a base for the skills. Though this would, in essence, just be a new skill line.
Or let us use one handed staff plus a weapon or shield.
Agree 100%
We already hold the staves in one hand most of the time anyway. Of course the staff would have to count as one item instead of two in such a case.
This would also liberate ice staves from the tank role, as tanking passives for staves could be tied to combining them with shields.
Though for someone trying to go for a purely mage aesthetic it would be nice with a non-physical shield motif of some kind. Perhaps resembling the wards of previous games; only appearing when blocking.