I think this would be great and only make sense because in Fallout 3 you purified the water, so the D.C. area should be thriving and the next game, (which should be a sequel) you have to pay for your actions.

Well, Fallout 4 should definitely continue the story of Fallout 3 (I'd love to know what happened to Vault 101, and it'd be especially cool if they turned out as some kind of superpower like how Shady Sands became the NCR, or perhaps a tribal group like the inhabitants of Vault 13), but I think it's best in the long run if Bethesda had some kind of canon sequence of events.

There is already an unfinished fo. Fo4 IMO must give a canon ending to and pick the story of the mid west bos from Fallout Tactics.

Its went without an ending for over 80 fo years and 10 real years.

Lyons bos can wait. They need more time anyway.

Its hard to say since Biowares games have been going by a main(and planned) story really which continues to the next game while fallout hasnt got a main story what goes though multiple games. it would be cool but just unless theres a major story cant see it going overly well. Also I dont think Fallout save game system can detect what the player has done.

Also if the game uses massive story endings like if the water is purfied or poisened or NV which faction takes over Vegas it could be abit much to carry on to other games without a defined cannon ending setting for the next game.

I think so, coming from the Elder Scrolls series, where each game got referred to (if only briefly) in the next one, I'd like to see something that mentions it. Even 1 character saying "my parents came from Megaton, imagine people living around a nuclear bomb" would be nice.

If you mean load up a Fallout 3 save file for Fallout 4 then no.

Absolutely not.

This.

But if you mean further consequences from canon events that we hear about in the hopefully new Eastern setting, then of course. I never want to return to the Capital Wastes unless we have a mad-node system that makes it so it isn't the only place we go. No Fallout location should be entirely focused on if it has been in another game, IMO.

That is true, carry-overs couldn't be too big where devs have to make a new game for each choice you make in the previous game. Mass Effect 2 just had cameo characters from previous game who survived some of your choices, and in-game news announcements, etc. Small stuff like that should be enough.

Given the massive difference in world outcomes, I think it would be hard to near impossible to have these unique to your playing experience.

Of course the previous games should affect the newer ones, otherwise the story wouldn't proceed. Plus to be entirely honest I'd love to hear a reference about the Courier.

This ^

But if you are just talkin about things in Fallout 3 being talked about in Fallout 4 then you have not been paying much attention to Fallout as a series because there are references to the past games in all the Fallouts. Not so much in Tactics but there are some.

Fallout 2 continues From Fallout and Fallout 3 has references to Fallout/Fallout 2 and even Tactics. New Vegas continues from Fallout 2.