Why do they suck? It seems that whatever team(since it quite frankly isn't IW) is working om MW3 are trying to work away from individual achievement in combat, as was the focus on every earlier version, and more into team play. Each killstreak has its own strategic value. I'll try to explain my reasoning for each one right now.
EMP grenade: Simply a form of disabling or otherwise handicapping the other team. This absolutely pseudoscientific device is probably one of the most direct, non-strategic killstreak rewards. Although if coordinated with the team, this could easily turn the tables on a game, this, likely to be the same 'expensive' killstreak as before is basically useless tactically.
Littlebird: Remember the Littlebirds from 2? Or that scene in Black Hawk Down where the helis provide close air support for the US forces? That's the idea from these. Possibly taking a hint from the UAV in Bad Company 2, this controllable weapon is like the Predator in the sense that it is a remote-controlled aircraft that you earn by killing people, and less like it in performance and execution. Presumably, the Littlebird can be shot down or destroyed, providing a more balanced weapon than the invincible, unstoppable Predator.
Precision Airstrike: This is such old hat I think you already get it.
Stealth bomber: This is also old hat. It's loud and big, so I still don't see how I can be called stealthy.
Remote Turret: Also old hat.
Directional UAV: It sounds like the player is allowed more control of the UAV, giving it specific areas it can scan rather than revealing the whole field. Other than nerfing the reward a bit, the area would also encourage more team effort; no point in the UAV if the team doesn't listen to you and attack where you have it scanning.
Remote Mortar: A more accurate version of the artillery strikes in WaW and airstrikes in MW2, the mortar sounds like a potential replacement for the Predator.
Airdrop Trap: Finally, you can pay back all those times someone tried to take your crate after knifing you! This is just so people have to be more weary when they try and steal crates.
Ammo Resupply: I'm assuming they got this out of the normal line up of random awards one gets when getting an airdrop.
Escort Airdrop: I guess they really wanna keep people from stealing airdrops.
Specialist Strike Package: Who. The. Fuck. Knows.
There'll be a video touting all of them in a couple weeks probably.
They're really working at nerfing killstreaks. I've looked a bit more into a couple of the new perks, more detailed at Kotakuhttp://kotaku.com/5805959/the-modern-wa ... illstreaks