PS Kudos to H0RSE because lots of the info is coming from the http://www.fragworld.org/frag/brink/the-fragworld-brink-compendium.html that he created
Abilities can be purchased when you level up be we now know they are based on rank, which is different from level.
There are 5 ranks:
R1: lvl 1-4
R2: lvl 5-9
R3: lvl 10-14
R4: lvl 15-19
R5: lvl 20
http://www.youtube.com/watch?v=AGUv0MoP5Qs Shows that many abilities can only be unlocked at higher ranks. For example the medic self revive (debatably OP) is rank 4, so you will at minimum have to be level 15.
http://img861.imageshack.us/img861/3277/universalabilities.png
8 of the 10 known universal abilities. The others being silent running and unknown.
Noted all except downed fire are rank 1 abilities. Meaning that you can gain them early one and since they are universal they are active no matter which class you are playing.
Engineer abilities: Shown at 42 secs on the new vid.
Rank 1.
Standard Engineer kit: Ability to repair objectives and buff teammate weapons. (Also looks like they may gets mines with the kit)
Rank 2.
Kevlar plate: increased armor (armor with upward arrows)
Gearhead (unknown ability)
Nerves of Steel: Quicker disarms (the hands)
Turret 1; First turret (the turret obviously)
Rank 3.
Upgrade command post: doubles command posts effect for team (computer with upward arrows)
Turret 2: Second more powerful turret ( slightly bigger turret)
Rank 4.
Increased mine capacity (mine with plus on it)
Improved weapon buff (gun with upward arrows) interesting you can't use the improved buff on yourself
Rank 5.
Gattling turret: level 3 turret and most powerful (biggest turret)
Medic abilities: Shown at 1:01 in the new vid (looks like lots of new buffs, pity we aren't shown what is what)
Rank 1.
Standard medic kit: ability to buff teammates health and toss revive syringes.
Rank 2.
Adrenaline: temporary invincibility buff, but you take all damage at the end. can't self apply
Transfer supplies: gives one of your supplies to a teammate
Supplies buff: makes your supplies regen quicker (unconfirmed)
Rank 3.
Fleet of Foot: boosts sprint speed (running man)
Rank 4.
Improved life buff, cannot be used on yourself
Self Resurrection: revive yourself when incapacitated with long cool down
Rank 5.
Lazarus grenade: AOE revive grenade
Operative abilities: Shown at 24 secs and 52 sec (because apparently everyone loves operatives :ninja: )
Rank 1.
Standard Operatives kit: Allows you to hack and disguise yourself.
Rank 2:
Firewall: allows you to firewall CP's which makes it harder for enemies to take it back.
Comms Hack: gain intel from downed enemies, makes enemies appear on teams radar for a short time (binoculars)
Sticky nade: A grenade that sticks to the enemy and they only get 5 secs to get a teammate to remove it or boom, replaces standard nade (spiked grenade)
Rank 3.
Smoke grenade: Releases smoke and caltrops that will damage any enemy that attempts to move through it (round grenade)
Hack turret: reprograms turret to be friendly, more effective when done from behind :spotted owl: (turret wit operative mask)
Rank 4.
Control turret: allows you to take control of friendly turret and use it in a first person mode (remote control)
Cortex bomb: allows you to self destruct when incapacitated (exploding head)
Rank 5.
EMP grenade: slows HE charge, disables turrets (EMP nade)
Soldier abilities: seen at 10 secs (lots of unknowns as well)
Rank 1.
Standard Solider Kit: uses HE charge, resupply ammo, and access to molotov
Rank 2.
Armor piecing ammo (possibly): ammo supplied is more damaging (shield with bullets)
Flashbang grenade: temporarily will blind the enemy
Scavenger: allows you to resupply supplies from dead enemies (bird claw)
Rank 3.
Kelvar armor: self armor buff
Incendiary ammo: Hand out incendiary ammo to teammates
Rank 4:
Increased explosive range (possibly)
Increased explosive damage (possibly)
Rank 5.
Satchel charge: Like c4 can deploy up to 3 charges that can be remotely detonated.
Well ladies and gentlemen that is my anolysis of the most recent info granted to us by our gracious overlords at SD. Feel free to help comment and speculate.