Unlike skyrim though, I would like to see the choices that you have made throughout your play through affect the game that is something that I have been wanting for some time.
I don't think this will be an issue. New Vegas was supposed to continue after ending, but Obsidian just didn't have the time to do all of the environment/dialog changes after the 2nd battle of hoover dam. They finished NV in something like 18 months as it is. They fixed the issue in Fallout 3 with Broken Steel. Bethesda has learned from these two incidents that people love roaming the wasteland after the main plot threads are done and over with.
Considering that there is a lot of open ended content involved (like building settlements) I see "continue after ending" as a near necessity, when you come down to it. Asking the player to invest time and effort into that, and then surruptitiously ending the game would be Punching the Player. That would not be cool to do.
http://www.gamesas.com/topic/1524382-please-dont-have-those-endings-like-in-fallout-3-and-nv/
Er ... huh? Bethesda Games Studios has a history of open ended games. And Bethesda games aren't games you 'beat' ... they are more like a place you visit.
This, Fallout 3 was the exception, probably done as Fallout 1 and 2 ended. However most of Fallout 3 players had played Morrowind or Oblivion and excepted the game to be open ended.