Nah the account thing doesn't bother me because at the end of the day it's just a forum account. For me it's just the respect thing. It's easier to be nice to others instead of being a dick and spoiling shit for them.
I usually don't like IGN, but they did a good rewind theater on the "Scanned" trailer.
They talk a lot about the fiction and how it relates to the trailer. A few "Fall of Reach" spoilers are in this so if you haven't read that and don't want it spoiled, I'd avoid this but if you had no idea what the trailer was about, check this video out. I learned a thing or two. Nothing spoiler-ish towards Halo 4 unless you don't know about the (Weapon and Enemy)
I haven't yet. But I don't really care about spoilers in anything, I usually look them up before I actually play/complete the game, I usually like to know what to expect, but for some reason, I feel like I don't want to know what happens in Halo 4.
With coordinated teams Personal Ordnance could be absolutely amazing. Not allowing the Drops to stack up so you can save one while you build another was a good choice, along with no meter building while in a vehicle.