I think many of the people on this wiki have forgotten about this announcement only last month. It states that this will be the only DLC for the single player campaign. It will not give extra game play after the crucible event. It will only further explain the ending in the hope to quell raging fans.
The link on Biowares' websight with the anounce ment is here
To me this is confirmation that they are definitely working on a Mass Effect 4 not DLC to add on to ME3. Hopefully this stops some of the incorrect comments about Bioware and money. They state in there it is the conclusion to Shepards' story. It does not state the end of the mass effect universe. Last year one of the writers of Mass Effect said in a interview with Good Game (an Australian show about gaming by gamers) it is definitely the end of shepards' story but not the mass effect universe, We will start with a new character instead of Shepard.
They state they will not change the ending and they are proud of what they made. Even though I hope this will reduce rage from the community I know it wont completely and maybe even inspire rage from the community. So by all means don't feel scared to post a rage comment as it is your right to do so.