ArenaNet calls their Thief a profession “unique" to Guild Wars 2 and, despite the many inevitable comparisons to the original Guild Wars Assassin, it is actually true. Team Quitter’s fifth profession overview enlists the help of Siege, a Thief fanatic with PAX experience who also happens to be the leader of 치 The Spearmen 치, a well-known multi-game guild. He’ll help us introduce you to some fresh and familiar features that make the Thief a rogue like no other.
http://www.teamquitter.com/viewtopic.php?f=55&t=26553

This one is really informative. (Not that the previous ones weren't, of course.) Siege gives some examples of Stealing, the pros and cons of the five weapon sets, and overviews the skills used in the thief teaser video. Strangely, this one doesn't have a tournament video as the previous ones did.


Quote Originally Posted by How does the Thief compare to the original Guild Wars Assassin?
“The original Guild Wars assassin was very combo-oriented. They ran up to you and used a series of attacks that worked only in that order, and then did it again and again. In Guild Wars 2, every profession other than the Thief is restrained by cooldowns, forcing them to use their skills together in this manner. The Thief is the only exception. The initiative mechanic allows the Thief to use any skill at any time, making them the most reactive (and least predictable) class in Guild Wars 2 - quite the opposite of the original Guild Wars assassin.

However, from a standpoint of mobility, the Thief doesn't disappoint. If you've ever played GW1 Random Arenas against an assassin runner who griefed your team by wasting ten minutes sprinting and teleporting around the map like a wild noob, you'll be distraught to hear that GW2's Thief can be every bit as obnoxiously mobile and slippery.”