Call of Duty: Black Ops - Confirmed Perks and Their Pro Abilities

One of the unique features that makes the newer Call of Duty games stand out from other first person shooters is being able to choose "Perks", or automatic power-ups that aid you on the battlefield. There is a variety of different perks, and you get to choose three different perks to help aid you. Each of these three perks that you choose are from three different categories. So, for example, you cannot have Scavenger and Hardline, as they are both Blue perks. The three different categories are categorized by three colors: Blue (Slot 1), Green (Slot 2), and Orange/Red (Slot 3). Each of these perks also have a "pro" ability, which gives additional aid to the player on top of the original perk. However, these "pro" abilities must be earned.

The following is a list of confirmed perks and their "pro" abilities:

Perk Slot 1
Lightweight - Allows the player to have increased movement speed. The additional movement speed is dependent on the gun the player is wielding and it's mobility. For example, an SMG has higher mobility when compared to a LMG.
Lightweight Pro - The player aims faster down the sight when sprinting.

Scavenger - Also called Scavenger in Call of Duty: Modern Warfare 2, the Scavenger perk allows the player to pick up ammunition off of fallen players. In Modern Warfare 2 the player would be notified that they have picked up additional ammo via an icon and sound when they resupplied.
Scavenger Pro - Doubles your amount of initial ammo by increasing amount of carried magazines.

Ghost - Essentially the Ghost perk is like the Camoflauge perk from Call of Duty: World at War and the Cold Blooded perk from Call of Duty: Modern Warfare 2. What the Ghost perk does is make it so that enemies cannot see you when an enemy Spy Plane is active, unless you fire your gun that doesn't have an attached silencer. Also, enemy air support such as Attack Helicopters cannot spot you.
Ghost Pro - The enemy will not see your name above your head when they aim their crosshairs at you. This is the same effect that was granted to Cold Blooded Pro users in Call of Duty: Modern Warfare 2.

Flak Jacket - Reduces the amount of damage taken from explosives. This perk was originally installed in the Call of Duty series in Call of Duty: World at War. In Call of Duty: Modern Warfare 2 this benefit was utilized through a piece of equipment called the "Blast Shield".
Flak Jacket Pro - Unknown at this time.

Hardline - The Harline perk was also introduced in Call of Duty: Modern Warfare 2. This perk grants you killstreaks for one kill less than it's value. For example, if you have the Spy Plane killstreak set and you get two consecutive kills without dying, you'll be granted the Spy Plane thanks to Hardline.
Hardline Pro - In Modern Warfare 2 the pro version of Hardline allowed players to get their deathstreak with one less death. However, in Black Ops, Hardline will grant the player the opportunity to randomly select a Care Package's contents if they don't like what it initially dropped. For example, if a player gets a Care Package containing a Spy Plane and they don't want it, they can try for another killstreak.

Perk Slot 2
Hardened - This perk grants the player additional bullet penetration. This perk was originally seen as "Deep Impact" in Call of Duty: World at War, and then again as an equipment attachment titled "FMJ" in Modern Warfare 2.
Hardened Pro - Unknown at this time.

Scout - Increases the time it takes to eliminate scope sway. This perk is essentially for snipers and was originally the pro version of Steady Aim in Modern Warfare 2.
Scout Pro - Unknown at this time.

Steady Aim - Increase the accuracy of bullets when hip-firing, rather than aiming down the sights. This is great for close quarters combat and when dual wielding.
Steady Aim Pro-Unknown at this time.

Sleight of Hand - Decreases the time in which it takes a player to reload their weapons by half. This perk is great for LMGs and for immediate danger zones where reloading is essential to stay alive.
Sleight of Hand Pro - Cuts the time in half in which it takes a player to aim down their gun's sights. It's been stated that this will not be available for sniper rifles.

Warlord - This perk is a renamed version of Modern Warfare 2's perk called "Bling". This perk allows the player to have two attachments on their primary gun, rather than one.
Warlord Pro - This allows you to have two attachments on both your primary and secondary weapons, just as Bling Pro allowed you to do in Call of Duty: Modern Warfare 2.

Perk Slot 3
Marathon - Marathon grants the player increased sprint time. However, unlike Modern Warfare 2's Marathon perk, it will not grant infinite sprint. It also will not increase sprint speed. The perk that Black Ops Marathon rivals from previous games would have to be the "Extreme Conditioning" perk from Call of Duty: World at War.
Marathon Pro - Unknown at this time.

Ninja - Grants the player utilizing the Ninja perk silent footsteps, increasing their ability to be stealthy. In Call of Duty: Modern Warefare 2 this was the Pro version of Ninja.
Ninja Pro - Unknown at this time.

Second Chance - When used the player using it will survive what would usually kill them, and drop them to the ground on their back with their pistol wielded, basically giving them a second chance to kill the enemy attacking them. One additional bullet will take out a player in Second Chance mode. If a bullet doesn't kill someone in Second Chance, then they will die anyway in 10 seconds.
Second Chance Pro - Unknown at this time.

Hacker - The Hacker perk is basically the same thing as the SitRep perk from Call of Duty: Modern Warfare 2. This perk allows the player using it to detect enemy equipment and explosives such as Tactical Insertions, Claymores, and even grenades.
Hacker Pro - Grants the player using the Hacker Pro perk to turn Care Packages into traps, and turn enemy killstreaks and equipment friendly. Example: Sentry Guns.

Tactical Mask - Mitigates the effects of flashbangs and concussion grenades when in use.
Tactical Mask Pro - Unknown at this time.

Other Information
According to my source for this information, http://www.cod7blackops.com/perks/, your first perk (the blue category) will determine the kind of armor your character wears for that match.