MMO Champion has data-mined Build 15762 of the Mists of Pandaria Beta and there are several interesting changes for hunters:
Baseline Abilities
- Kill Shot now does 300% weapon damage, rather than 85% weapon damage plus (45% of RAP + 512).
Talents
- A Murder of Crows: If used on a target below 20% health, the cooldown is reduced to 15 seconds rather than reset.
- Glaive Toss The primary target will take 8 times as much damage from each strike (up from 4).
- Narrow Escape now lasts 8 seconds rather than until canceled.
- Posthaste Disengage frees you from one movement impairing effect (new) and increases your movement speed by 60% for 8 sec (up from 4).
New Hunter Gear
- Gauntlets of Bloody Judgment
- Saboteur’s Locket
- Scarlet Archer’s Links
- Mantid Exterminator’s Cloak
- Inscribed Bloodmail Hauberk
- Leggings of Forceful Instruction
- Bracers of Swift Wrath
- Cowl of Internal Strife
- Elemental Archer’s Links
- Terror in the Mists
- Ranger’s Chain of Unending Summer
- Chestguard of Earthen Harmony
- Raiment of Blood and Bone
- Raven Lord’s Gloves
- Gloves of Earthen Harmony
- Quick Strike Cloak
Season 12 PvP Gear
- Contender’s Dragonscale Boots
- Contender’s Dragonscale Chestguard
- Contender’s Dragonscale Helm
- Contender’s Dragonscale Leggings
- Contender’s Dragonscale Bracers
- Contender’s Dragonscale Belt
- Contender’s Dragonscale Shoulders
- Contender’s Dragonscale Gloves
For a complete list of changes see the original post at MMO Champion.