The nether disruptor is up with the "get one extra roll each day for three days" buff.
The command center will be coming up with the "get a free piece of legendary follower equipment" buff, probably in 3-5 days (the mage tower is ahead so will likely be built first, with a less interesting buff).
LFR Kil'Jaeden is available for the first time this week, making the rank 2
Vantus Rune: Tomb of Sargeras recipe available to non-raiding characters. Expect some wipes if you do it this week. Armageddon is the main raid-wiper. The debuff from soaking a small armageddon patch does not stack in LFR, so people can soak consecutive armageddons. Having adds up going into the second transition is also likely a raid wipe, so it's important for people to stack those on the boss to be killed quickly.
There are doomsayers in the capital cities, with new and sometimes amusing pamphlets. I'm not aware of any achievement for collecting the pamphlets this time around. wowhead had an
article if you just want to read the pamphlets offline.
Argus is visible in the skybox for everyone, not just players who have killed KJ.