There are three Achievements, each worth 50 points, bringing the game's total to 1200. The Achievements give us a few details about the DLC's contents. According to the descriptions, Commander Shepard should take part in "Ahern's survival mission" as well as several "combat scenarios on Pinnacle Station." Sounds like we're getting that fight club after all.
We've contacted BioWare in hopes the company might finally drop some details. We'll update this post with any new info.
[Via X360A. Thanks, Jp!]