Joystiq, via BioWare Forums, is reporting that with the latest game patch, the new DLC is revealed through the updated trophies.
One of the Trophies, "Covert Action," refers to a Dr. Amanda Kenson, who was previously mentioned in a recent Cerberus Network update:
Historians and astronomers alike are abuzz tonight over a new paper published by Dr. Amanda Kenson of the University of Arcturus ... "Only a small fraction of the mass effect relays date back 50,000 years," she writes, "The majority are far older, indicating they were created by a species predating even the Protheans." ... What civilization could have spanned the galaxy for not thousands, but millions of years? If this were the case, we should have found mountains of evidence of their passing. Where is this species now?"
Some believe that "Arrival" can refer to the arrival of the Reapers, setting up events for the upcoming Mass Effect 3. Others, however, are more fixated on figuring out how to acquire one of the more ominous Trophies for the DLC: "The Ultimate Sacrifice." Wasn't dying once sacrifice enough?
This isn't the first time that details have been revealed about a EA DLC via a trophy update. In the Battlefield: Bad Company 2 Ultimate Edition, all of the trophies from the Vietnam DLC were preloaded on the disc.
To further "confirm" this new DLC, Inside Gaming's Adam Kovic (Dead Pixel) recently attended a EA event at which he & the rest of the IG staff arranged an agreement not to talk about a certain upcoming DLC until February 25th.