Fallout: New Vegas has an end and Obsidian says they aren't going to change that. DLC will need to be played before the final quest.
http://www.1up.com/news/fallout-new-vegas-definitive-ending
"We want to make it a definitive ending. Initially, we talked about trying to support post-game play, but because the changes that can happen at the end of the game are pretty major, this is what it basically came down to: either have the changes feel really major in the end slides and then have them not be very major after the end of the game, or make them really minor and not that impactful. And we feel it's better to say, 'you know what, we're just going to end the game, and the changes you made can be minor or really really big, but because we can't script all the changes to the Wasteland to let you keep playing, we're just going to stop it there.' But we do let the player know when that's about to happen-- a sort of, 'the end of the game is coming, so we're saving your game right now, so if you want to keep your game going, you can, otherwise, it's about to be over.'"
http://www.destructoid.com/fallout-new-vegas-has-a-definitive-end-181927.phtml
We tell the full story of every one of your companions through the end of their lives, and it's weird to do all that and then jump back and say, "Okay! Now you can keep going again." So we end the game, and if you want to do other quests, then you go back to that save game before the end sequence.
The way Bergman explained the structure of the ending to me made it sound like Bethesda won't do something as clumsy as the retcon of "Broken Steel" again, in order to justify the add-ons for New Vegas. We'll have to wait and see.
There. Now nobody can say that I made it up. Check for yourself.
Weep, Broken Steel fans! Weep until your eyes bleed!
» Sat Aug 23, 2008 3:17 am 
... Hello NV forums! 
