When SBS Gaming asked Kristoffer Bergqvist ontwitter if peak/lean will be in Warfighter's Multiplayer he said "Yes! Warfighter MP will absolutely have Peek/Lean. Sorry about the lag getting back to you, I'm a bit busy chasing bugs."
Now all I need is the ability to swim and dive, slide, and for the Demoliton class to yell "There be gold in dem der hills" and i'll be happier then this.