Stealthers Seeing Others in Stealth
Assuming stealth skill is at 50

Assassins see other assassins at a range of 125.
Assassins see archers at a range of 250.
Assassins see Minstrels at a range of 250.
Archers see assassins at a range of 125.
Archers see other archers at a range of 125.
Archers see Minstrels at a range of 125.
Minstrels see assassins at a range of 125.
Minstrels see archers at a range of 125.
Minstrels see other Minstrels at a range of 125.

Mastery of Stealth
Mastery of Stealth is no longer a Realm Ability, instead you get it for free based on your stealth spec:
10 Stealth Spec: Mastery of Stealth 1 +10% movement speed
15 Stealth Spec: Mastery of Stealth 2 +13% movement speed
20 Stealth Spec: Mastery of Stealth 3 +16% movement speed
25 Stealth Spec: Mastery of Stealth 4 +19% movement speed
30 Stealth Spec: Mastery of Stealth 5 +22% movement speed
35 Stealth Spec: Mastery of Stealth 6 +25% movement speed
40 Stealth Spec: Mastery of Stealth 7 +28% movement speed
45 Stealth Spec: Mastery of Stealth 8 +31% movement speed
50 Stealth Spec: Mastery of Stealth 9 +34% movement speed

Poison Changes
The enervating poison (strength / con debuff) has been changed to a weapon stat / con debuff.
The weapon stat debuff works similar to a weapon skill debuff: For all combat rolls the debuff is applied to the stats that count towards your weaponskill. The stat is not actually debuffed outside those calculations and does not show up on your char screen.

~~Examples with a 118 weapon stat / con debuff against a level 50 target:
When applied to a Shadowblade (only has access to 100% strength weapons) with 300 strength: the Shadowblade will see their normal strength value, the carry capacity is not reduced but defense penetration and damage rolls act as if he had 182 (300 – 118) strength.

When applied to a Reaver with a flex weapon (50% strength, 50% dexterity) with 300 dexterity and 300 strength: the Reaver will see their normal strength and dexterity values, the carry capacity is not reduced but defense penetration and damage rolls act as if he had 182 dexterity (300 -118) and 182 strength (300 – 118) (the exact formula here is: ((strength + dexterity ) / 2 – debuff value). The evade and block chance is not affected by this dexterity debuff.

When applied to a Friar with a staff (100% dexterity) with 300 dexterity: the friar will see their normal dexterity value, defense penetration and damage rolls act as if he had 182 (300 – 118) dexterity. The cast speed and evade chance is not affected by this dexterity debuff.

Nightshade cast damage (Nightshade acuity stat is dexterity) is not affected.