I've have definitely considered this as a feature. The largest thing preventing me from jumping on this idea fully is the large majority of hardware raid controllers. Things would be easier if smartctl used the same parameters hard or soft, but hardware raid makes one virtual drive, whereas software raid leaves the drives exposed.
With SWR the call to smart status is:
smartctl -a /dev/sda
smartctl -a /dev/sdb
With HWR the call to smart status first requires a call to the raid controller to get the device IDs then a specific call to smartctl for the raid controller + ID:
smartctl -d megaraid,4 /dev/sda
smartctl -d megaraid,5 /dev/sda
smartctl -d 3ware,1 /dev/tw1
smartctl -d 3ware,2 /dev/tw1
The list goes on.
Further, I'm not sure how people would react to giving apache smartctl privileges. Feel free to discuss