If you want to see all known info about 2.4 items, go to http://www.worldofraids.com/
. So far, we know the following:
Magister's Terrace has Kael'thas as the boss and he drops epics on both normal and heroic modes.
Sunwell raid trash drops Sunmotes which allow you to upgrade existing gear and (apparently) convert your T6 set pieces to their alternate spec equivalent(s). Sunwell boss tokens will let you get boots, bracers, and belts for your T6 sets. There are no new confirmed set bonuses.
All raid bosses (10- and 25-man) will drop Badges of Justice.
All 25-man raid bosses drop an extra set token (assuming they already drop one to begin with) and drop more gold.
The new badge gear is item level 141 (as opposed to 128 for current badge gear) and is therefore equivalent to Black Temple drops. The requirements to obtain these are not yet known, but you will almost certainly need to gain reputation with the new faction, which is earned through daily quests.
All drops from Doom Lord Kazzak and Doomwalker are now Bind on Equip.
Primal Nethers and Nether Vortexes are no longer Bind on Pickup.
And there's no new pally tanking weapon. Not that you had to ask.