I'm a fan of the support killstreak in mw3 and i hope it carries over into black ops 2, the support killstreak is the only killstreak i use, im guaranteed to help my teammates and that's what its all about.
I support my team mates using Assault + Hardline Pro. My killstreak is set to UAV with nothing on the second and third slots. I get a UAV every 2 kills and I spam them. I keep the enemy team lit for the entire match. I also found out that it has a certain psychological effect on them and it makes them feel uneasy and forces them to change their gameplay.
I have 1 class like that. I run UAV and CUAV and average calling each one in 4 times a match. Sure it's annoying, but might as well since the majority of the players are going to have Blind Eye and Assassin, sitting in a damn corner somewhere. Screw 'em.