It has been confirmed that there will never be a Borked Steel DLC for FNV. It was publicized long before the games release that there would be a definate ending. There are many people who are angry, but the majority of people seem to prefer it this way, as our choices in the game are far-stretching and meaningful, and those implications have big effects in the years after the ending, and post-MQ gameplay would be unable to properly show it, so the end is closed and a good game should get good ending slides showing the consequesnces of your choices throughout the game.