When Gearbox first showed a video teaser for it's next DLC character during SXSW, what made its way onto the 'net was video OF the video, and a bit blurry, grainy, shakey one at that. Gearbox has since released the clip itself online, allowing for a better look.
Gearbox hasn't released any other information regarding the upcoming character, but they seem to have their hands full in dealing with the "Aliens: Colonial Marines" debacle.
As the trailer alludes, we'll find out more about the character once PAX East starts, March 24th (maybe sooner, DLC info has leaked out in the past). The character will be joined by an increase to the game's level cap, so that players can get the most out of him...or her, or whatever the hell it is.