Well, this isnt written in stone but I'm pretty certain that...

Sorry for the spoilers, but there is no spoiler section.

We already know that the game has a definite end. This isn't news. However, if the ending is good enough I don't think we need an add-on like BS.

It's possible but by no means guaranteed. Never-ending sandbox games are the exception to the rule. Most games have a story, and done properly, the story has a satisfying conclusion and maybe some epilogue stuff. You saw how it turned out when Bethesda tried to address a world-changing event within the game through DLC dedicated to that purpose. Did you like the result?

My guess is that they want the ending(s) to noticeably affect the game world, which would be difficult and pointless to actually try to implement in-game, rather than through cinematics or exposition.

:slap:

Actually, I did like it. I was very satisfied with the endgame originally, but I also liked being able to continue, as a sort of a winding down epilogue. You got to see what your actions did, and you got to help out (or exploit) the people who were working with said actions. In my opinion, there was no "better way" of doing it. After all, Broken steel was DLC, and wasn't required at all. But for those that wanted just a little bit more, like taking on an entire base to blow stuff up.
I don't mind either way if Bethesda adds in another DLC ending, I just want to play an awesome game.

There are already several topics on this, http://www.gamesas.com/index.php?/topic/1098428-ending/. No need for another.