If you can't see the wow forums for whatever reason, here is the quoted post:
Q u o t e:
2.4 is planned for before years end.
As far as penetration, my belief is that there's no reason it shouldn't be 100% scaling. The reason behind this line of thought is that demon abilities are considered to be part of the warlock class; things like Spell Lock, Devour, Seduce, etc are all taken into account when you consider the whole 'warlock equation'.
Having them not scale at the same degree of the warlock itself is akin to adding "more susceptible to resistance" to the tooltip of Counterspell.
I'm inclined to agree. I think we're seeing 3 problems here.
A) Paladins are too easy as is to CC and stop from healing their teammates. They don't really have any meaningful instant heals or oh-@!!@ heals. This problem leads to:
B) Paladins stacking things such as: http://www.wowhead.com/?search=shadesteel This problem leads to:
C) Warlocks then needing to stack massive amounts of spell penetration to negate shadesteel or other similar SR gear pieces as best as they can. This does not help pets, however.
So the REAL underlying issue isn't necessarily pet scaling with spell pen or the lack thereof. The REAL issue is the fact that paladins feel required to do whatever they can to make up for the fact that a warlock can CC them into oblivion without even trying. I will be the first to say that it is, currently, much too easy to completely shut down a paladin for most of a match, and at any given critical moment at will, minus when he's bubbled for a trivial amount of time.
So rather than sticking a bandaid on top of a bandaid (ad nauseam), Blizzard is currently trying to first see if they can find a better solution to the actual REAL problem, if that makes sense
I hope that clears some things up for you."