Perks will be broken down into 3 tiers as it was in other Call of Duty titles, but there’s a new proficiency slot added. These are the confirmed perks in Modern Warfare 3:

Perks:

Slot 1: Recon, Extreme Conditioning, Blind Eye

Slot 2: Quickdraw (like sleight of hand),  Assassin,  Blast Shield (like Flak Jacket), Overkill

Slot 3: Stalker, Sitrep, Dead Silence

Proficiency:

1) Kick

2) Focus

3) 2 Attachments