Official Blizzard Quote:
We think it's probably time to let pets scale, to some extent, with resilience and spell pen.
The way pets scale from the master's stats was implemented (on our side) in a slightly clunky way which made it difficult to add additional stats. In BC, it took some effort to kill a pet so it wasn't a burning problem for us. In LK, we have bumped up pet health a few times, but we are thinking now that the balance will never work right without some crit mitigation. Pets will never scale right with gear as long as the master improves in ways that don't benefit the pet.
We have a new way to let pets scale, and assuming it works, we should be able to give the pets scale with all relevant stats from the master, from hit to haste to crit. Some things will need to scale at 100%, since it's silly to have your pet inherit part of your +hit.
No promises until you actually see it live, but that's what we are thinking at the moment.
Ou llea.