From wow.incgamers.com

Statistics

• This skill requires the Shadowstep Talent

Talent Improvements

Subtlety Tree

Talent: Shadowstep Talent
Effect: Attempts to step through the shadows and reappear behind your enemy. The damage of your next Ambush, Backstab or Garrote ability is increased by 20%. Lasts 10 sec.
Statistics: Cost: 10 Energy, Range: 20 yards, Cast Time: Instant, Cooldown: 15 secs, School: Physical, Form: Stealth.

Threat Level

This skill causes no amount of Threat.

Uses in PvP

Please feel free to add a bullet list of uses within PvP or editorial if you have more to say. What use is it against other builds, what skills can it be used to counteract or prevent. What skills does it work well in combination with.

Uses in PvE

Please feel free to add a bullet list of uses within PvE or editorial if you have more to say. Which creatures/bosses in particular is it useful against. What skills does it work well in combination with.