There are 4 that I can see being overused/OP
http://www.youtube.com/watch?v=1yZ6VV6iYBM&feature=plcp
The Type 25, an automatic, low recoil assault rifle
The M8a1, a 4 round burst weapon
The Skorpion Evo 3, a weapon similar to the MW3 PP90m1
And the Ballista, a sniper where you can use just the iron sights
What do you think?