Borderlands 2 concept art for the Assassin, Siren, Commando and Genzerker have popped up online.
There's also an updated FAQ for the game posted over on the game's official forums, and while it doesn't contain any new information, it should answer any basic questions you may have lingering around in your handsome noggins.
The concept art mentioned previously, is posted below, courtesy of AGB. Likely you already saw the shots during IGN's coverage of the game, but this will provide you with a closer look without clicking all over the place.
Borderlands 2 releases September 18 in the US and September 21 in Europe for PC, PS3, and Xbox 360.