while blowing megaton was fun and having harold multiply adding some braches outside ( or was it wishfull thinking ?) I was wondering is there any major change in game world based on your own actions?

a couple of things I'd like to see either at day one or later dlc would be

1 some base that you can recruit and equip people to, also to expand through quests. I always seemed to end up having way more armor and weapons available than it was resonable to use or sell. something like the caravan trade in f3 but with more meat on the bones wouldn't hurt either.

2 point look out kind of dlcs with more stuff to do , or say mothership zeta + crew mod, arefu expanded with caravan mod, stuff that actualy involves the player in its development. I thoroughly enjoyed morrowind base building or the final quest/recruting armies of oblivion.

3 but no last : any chance to see some sort of link with the new brotherhood forged infallout tactics?

If they were to do something like this. I hope it's like the Modoc Outhouse quest.

Nothing has been released that relates to changing the 'Game World' in any way. Don't expect them to release anything like that. This is a wait and see sorta thing. However it would be nice to see something like this. I know in a preview

in this game you cant just shoot up primm. then come back 2 days later and all be forgotten. the reputation seems to have fixed this

You sure it wasn't just C-4?

I know what he means, in some of the trailers you see rockets flying and one hits a spot be it whether in New Vegas or not.