Good evening.
Because many People wondering about multiple World States or Save States on the PC or Console it self (and as there is only one Explanation on a Twitch Stream from Mike Laidlaw yet), i try a simple explanation here. And it is very very simple. Well you need a Internet Connection of course.
To have different and multiple World Plot States from the Keep in DA:I, you have to:
1.) Login to the Keep
2.) Export World State 1 to DA:Inquisition.
3.) Start a New Game and select that World State.
4.) At the next possible Point, make a Manual Save.
5.) Voila World State 1 Imported saved for later use.
6.) You can now Play the Game or exit to the Game Main Screen, if you want to Import more Custom World States.
To Import another Custom World State:
7.) Export World State 2 to DA:Inquisition.
8.) Start a New Game and select that World State.
9.) At the next possible Point, make a Manual Save. Now You have World State Number 2 successfully saved for later use.
10.) Again: You can play the Game or repeat the above Steps to Import another World Plot State.
A small Q+A:
Question: If I Import World State 2, do I lose World State 1?
Answer: No. Not officially stated by the Devs but to repeat my self: It would absolutely make no sense. Or Mike Laidlaw would not have mention the possibility, to have multiple World Plots saved on our End.
Question: Will this only work on PC?[*]
Answer: I am not a Console Player. But I am sure it will work on Consoles too. Would make no sense to limit it to PC only 
Question: Can I backup the Savegames with the different World States?[*]
Answer: On PC: Yes. I am sure we can. The Frostbite Engine creates Standard Savegame Files within the User Folder.
We dont know the exact Path Settings yet. But the Savegames should be somewhere under
<UserName>\MyDocuments\blablabla or <UserName>\SavedGames\blablabla. Not sure what Variant is used by the Frostbite Engine.
On Consoles: I have no Idea if there is a way to Access the Savegames and back them up. Eventually there is a Description somewhere on the Internet. Sorry.
Question: How many World States can I Import and Save on my PC or Console at the same time?[*]
Answer: The exact Number is not known yet. I personally think at least 2-5 or 2-10 on PC. If it is somehow limited at all.
Question: Do you violate the NDA?
Answer: NO. I do not.
All Infos are officially available from the Keep and / or the DA:I Team itself. Be a Twitch Stream or a Twiiter Mention.
[*] = This Info will be updated with the Correct Information as soon we get them officially.
And now: Here is the Link to the Twitch Stream from September 29, where Mike said, we can have multiple World States. Look at: Minute: 22 Second: 33
http://www.twitch.tv...are/b/573285688
This post will be updated as soon we get the rest of the Infos. Will latest be at the Release Date.
Have a good one.
Oliver
Yep, essentially - and if you need more than the world state slots we provide, you can overwrite any WS if needed. For example, once World State 1 is in DAI, you can change WS1 again on the Keep to be a different history and start yet another new game in DAI and import that new WS1 into that. So you are actually just limited by whatever DAI save file limit there is per platform (which I don't know off-hand, but in previous games I think this was up to 99 on console, and unlimited/hdd space on PC).
If you import WS2, you do not lose WS1 in DAI - unless you specifically choose to overwrite the DAI save file.
Other than any usual platform specifics around handling save/load, there are no differences between what you can do in DAI when it comes to importing Keep WS. That also includes how these save files are typically physically stored on the local system, and can therefore be copied & backed up if needed.
Someone mentioned needing to be offline around xmas - and ya, you can totally start as many new games as you want (up to platform limit) each with a different world state before then. Just remember to make a note of which save is which 
Is the keep getting wiped before release?
Should I make my game imports, or wait until it's really done.
There's no plans to wipe, so what is there should be what you can use with DAI. That could change, as things are in a beta after all, but so far we've been fortunate in how its been built that we have not needed to, even as we expand the story choices available thanks to the beta feedback - so i'm not expecting that it would change at this point.
So, could I simply create characters in DA:O and DA2, save after the little opening intro and have them sync to the Keep - and not actually play the characters through the storyline (as I'd have to recreate the playthroughs on the Keep anyway)?
Yep. The DAO stand alone character creator was a good example of that, but also firing up the previous game just to do chargen & then save should also work. In the case of CC, since that is also using the same Origin account as the previous games, DAI and Keep - you actually could use the DAO PC CC to create a hero appearance, and use that in Keep after it syncs - even if you only played DAO on console (or never) for example.
Again, the only thing we bring over from DAO & DA2 is 1) the hero avatar image & name - as a way to help you identify a particular hero you might want, but with no bearing in DAI itself for example. And 2) that hero's story related attributes, specifically gender, class, race (and origin story) which can adjust story choices in Keep.
If you are not concerned (or for whatever reason unable) getting your DAO/DA2 hero in Keep, you can easily use one of the defaults provided - there is one provided for every gender, class, race, (origin story) combo - and you would be getting the exact same experience as someone who imported.
In fact, you could use a default hero with same attributes (ie. female, elf, mage), and at some point in future (you replayed DAO, or used the CC, or synching fixed an outlier that previously prevented your hero synching) change that to your actual hero (also F.E.M.) and the story would stay exactly as is and you would lose nothing.
Hope that helps
F.