I've acually beaten Lonesome Road, but I haven't beaten the end of New Vegas after having beaten Lonesome Road. I'm gonna go out on a limb and say it doesn't add anything to the end of the game and if it does, it isn't much. I figure *spoilers* a nuke going off on part of Caesars Legion's army would effect them, if not in numbers, then at least in morale. It reminds me of going into Caesars camp, killing everyone including Caesar himself and having no real effect on the ending, everyone was like "Cool story bro". Anyway, that's just my thought.

There is a spoiler thread..

Damn, sorry I just saw the spoiler thing, this will probably get closed.

My bad, I'm new to this forum.

Cool, they moved it for me.

No none of the dlc's alter anything within the main game with the exception DM and Veronicas dialogue and update for HH adding 45 ammo and weapon mods to the gun runners, theres no affect on the actually story of New Vegas.