It's interesting to me that none of the bigger game sites have commented on this story. I wonder if EA or BioWare has an embargo in place to keep them from talking about it. IGN and Gamespot haven't said anything.
Either way, I think this will most likely be the final DLC meant to be completed after the suicide mission. Shepherd won't be the "Ultimate Sacrifice," because that wouldn't make sense. It will be some NPC you meet as part of the DLC