When do Rogues learn Stealth?

Rank 1 at level 1, with later ranks at 20, 40, 60. Visit a class trainer in any capital.

Did Stealth change from Classic?

No recorded differences from Classic 1.12 in this snapshot.

Rank	Level	Cost / range / cast	Effect	Classic 1.12
Rank 1	1	Instant · 10 sec cooldown	Allows the rogue to sneak around, but reduces your speed by 50%. Lasts until cancelled.	same
Rank 2	20	Instant · 10 sec cooldown	Allows the rogue to sneak around, but reduces your speed by 40%. Lasts until cancelled.	same
Rank 3	40	Instant · 10 sec cooldown	Allows the rogue to sneak around, but reduces your speed by 35%. Lasts until cancelled.	same
Rank 4	60	Instant · 10 sec cooldown	Allows the rogue to sneak around, but reduces your speed by 30%. Lasts until cancelled.	same

Master of Deception (Subtlety row 1): Reduces the chance enemies have to detect you while in Stealth mode as if you were 3 levels higher.
Ghostly Strike (Subtlety row 4): A strike that deals 125% (180% if a Dagger is equipped in your Main Hand) weapon damage and increases your chance to dodge by 15% for 7 sec. Awards 1 combo point. Also causes your next Ambush or Garrote cast within 7 seconds to not require Stealth.
Heightened Senses (Subtlety row 5): Increases your Stealth detection as if you were 3 levels higher and reduces your chance to be hit by spells and ranged attacks by 4%.

Source: beta client 1.60.1.70753. Spell ID 1787.