Decent talent for short fights (leveling). An alternative is Elusiveness.
Great talent for pvp and dungeons. Useful while leveling because it allows you to isolate targets. Note: make sure to have Vanish ready if you are sapping in dungeons. If you don't want take Initiative.
Not that great, but is needed for Hemorrhage.
Great talent, replaces Sinister Strike and builds combo points very fast due to the low energy cost.
The best pvp talent you can get. This will allow you to escape sticky situations and make big plays.
Increasing the duration to 6 seconds allows you to re-stealth after gouging in pvp. While leveling the increased duration will allow you to regenerate more energy while the enemy is incapacitated.