You're nuts if you don't think it does anything; they also nerfed the flat ArPen by 5, as well.

The previous break even point for Last Whisper to beat Black Cleaver (at full stacks) was ~320 armor (this factors in the 8% ArPen from masteries)---now, Last Whisper beats Black Cleaver at 100 armor or above, and this is a fully stacked cleaver.

There's really no point to Black Cleaver anymore aside from acting as an amp for your team---under selfish conditions, Last Whisper is almost always going to be a better choice; especially if you already have Brutalizer. If these changes go through I predict very very few individuals will ever pick it up once the newness wears off and people start building logical non-silly builds.

It's unlikely that the ADC will get Black Cleaver; it effectively means they're giving up blood-thirster for it; they'll gain a bit of a boost in DPS (only at full stacks, meaning the 5th attack onward) in exchange for absolutely no survivability. As for non ADCs getting TBC+LW? Even less likely.

Take into account the old rammus, malphite, and amumu. in their primes, they did massive amounts of aoe damage, had great cc, and NEVER DIED. That was the problem. Problem is now fixed.

Note: The Armor pen now goes percent armor pen than regular armor pen.