1) Sell off Defiled Augment Runes, as a new permanent rune will be available to those who reach exalted with Army of the Light.

2) Buy off/hoard obliterum, they will likely see a big price increase seeing as they can be used to increase the item lvl of crafted gear further than in the current patch.

3) Buy/craft goblin gliders, they might sell well seeing as the new zone will have flying disabled.