Here's how I am running the half-orc as of right now.
+2 Strength, +2 Wisdom or Charisma, -2 Intelligence: Half-Orc's are strong, and can be very wise and have strong personalities, but they tend to be unlearned.
Medium: Half-Orc's are Medium creatures and have no bonuses or penalties due to their size.
Normal Speed: Half-Orc's have a base speed of 30 feet.
Darkvision: Half-Orc's can see in the dark up to 60 feet.
Intimidating: Half-Orc's get a +2 bonus to intimidate checks due to their fearsome nature.
Orc Blood: Half-Orc's count as both humans and orcs for any effect related to race.
Half-Orc Ferocity: When the half-orc gains the Bloody condition (obviously 1/2 max hp or less), he gets a +1 bonus to attack rolls.
Powerful Blows: Whenever the half-orc deals damage with a melee attack, he adds 1 ½ times his Strength modifier to the damage (he adds twice his strength modifier when attacking with a two-handed weapon).
Languages: Half-orcs begin play speaking Common and Orc. Half-orcs with high Intelligence scores can choose from the following: Abyssal, Draconic, Giant, Gnoll, and Goblin.
Ugh, I hate the "big and dumb" stereotype for Half-Orcs, and I was super happy when Paizo finally nixed it. However, most people (particularly legacy enthusiasts) on the forums seem to disagree so I won't fault you there.
Going between a bonus to wisdom or charisma is very unusual for the system, and sort of goes against the "racial profile" concept of racial bonuses to stats. An argument could be made in favor of this because of humans and half elves, but it still seems odd. Personally, I'd nail them down as a +WIS race because the +2 intimidate hints at a higher charisma. Regardless, it's not unbalanced; just unusual.
Half-Orc Ferocity: I see you're pulling from 4E terms. :) As far as this goes it looks pretty balanced. I'd probably expand on your description though and state that the half-orc gains a +1 bonus to attack rolls as long as she has fewer than half hit points.
Powerful Blows: I like it- it's a nice little bonus that fits your concept of the race perfectly. It's balanced just fine so long as this ability doesn't interact with offhand weapons and the power attack feat.
lol
4e has Bloodied.
I gots Bloody. :)
In my original document i did a long write up about the 1/2 hp, and then just decided to make a new condition called Bloody. ;)
For those NOT in the know, Bloody: Your character's current hit point total is at 1/2 or less his maximum amount.
heh heh ;)
It looks like a better version of the Beta Half-orc.
I would also stick to +2 Str, +2 Wis, -2 Int.
I would also suggest making some alternate racial features for non-combat half-orcs.
For example,
Blood Magic: When the half-orc gains the Bloody condition (obviously 1/2 max hp or less), he gets a +1 bonus to the save DC of any spell he casts.
This replaces the standard half-orc's Half-orc's Ferocity.
Powerful Senses: The half-orc grew up in a deadly environment where he was constantly on the look out for danger; he adds 1 ½ times his Wisdom modifier to Perception, Sense Motive, and Survival skill checks.
This replaces the standard half-orc's Powerful Blows.