From what I remember from wowexposed, there are 3 new paths to tailoring. (Like Armorsmith/Swordsmith/etc for Blacksmithing) The paths are Mooncloth (healing and stats type gear), Netherweave (shadow and arcane I think), and Spellweave (fire and frost). I may have those names a little wrong, but those are the 3 basic paths.
There are new types of mooncloth and other cloths that have a cooldown and require a moonwell.
There are also uber "armor kit" type thingies. I think they are called "enchanted threads" and can be applied to head and leg armor (I think it's head and leg) and give you +spell damage or mana regen, or whatever.
There are lots of new bag types. Some were profession bags (mining for example) but others didn't have names that reflected any trade. Bliz may be adding in craftable 20+ slot bags. Blues have recognized the current inventory problem. Maybe this is how they plan on fixing it?
That's about all I remember. The 3 branches bum me out because I like to be able to learn everything, but I assume we will coordinate within the guild so that we get tailors of all branches.