This is just what I've noticed up to now. Some things are not yet implemented or I'm not the right level to try them out yet.
Beast Master Ability Changes
Beast Cleave: level 24 BM ability. After you Multi-Shot, your pet’s melee attacks also strike all other nearby enemy targets for the next 5 sec.
Kill Command: level 10. Changed to BM only, and works as long as your pet is within 25 yards of the target.
Bestial Wrath: cooldown lowered to 1 minute, down from 2 minutes.
Beast Mastery: changed so that it still allows the taming of exotic pets but instead of giving extra pet talents it lowers the cooldown of pet specials by 30%
Survival Ability Changes
Black Arrow: deals some direct damage to the target in addition to the DoT, Lock & Load will only proc from the DoT on your target. Now has a 2-second cast time.
Viper Venom: You gain 3 Focus each time your Serpent Sting deals damage. This effects has a 3-second cooldown.
Marksman Ability Changes
Steady Focus: new version of Improved Steady Shot. When you Steady Shot twice in a row your ranged attack speed will be increased by 15% and your Steady Shot will generate 3 additional focus for 10 sec.
General Hunter Ability Changes
Hunter’s Mark: Changed to increase damage by 5% on the marked target: and duration is 30 seconds for PvP and 5 minutes for PvE.
Aspect of the Hawk: Also changed to 10% AP
Trap Launcher: Changed to a toggled ability. If it’s toggled on, every trap you use will be launched. If it’s toggled off you drop traps at your feet like normal.
Kill Shot: If the Kill Shot does not kill the target, the cooldown is instantly reset
Trueshot Aura: now a passive ability available to all hunter specs that gives both 10% melee and ranged Attack Power and 5% critical strike chance.
Camouflage: can be cast while in combat, but if it is you only get a 6-second duration.
Stampede(Name Not Final): level 87 ability for all hunter specs, Stampedewill let hunters bring out their active stable of pets all at once for a short duration, long cooldown.