T-Mobile today unveils a new ad campaign that speaks to the carrier’s challenger mentatility and upcoming fall brand re-launch.   The first teaser clip, online already, shows the company spokeswoman and brand ambassador , Carly, as she sheds her magenta dresses and dons leathers.

Called “Alter Ego, the ad is to be considered a metaphor for T-Mobile’s position in the industry as provider willing to take on bigger players.  The ads and branding are said to be more bold, tech-ier, and sexier and all about the carrier’s 4G network speeds. A teaser clip can be found below, (UPDATE) followed by the full 1:00 clip.

In addition to the new look for Carly, T-Mobile is also unveiling a Test Drive site where they encourage visitors to compare the network speeds as they compare to other wireless providers.