Nentir Vale sounds like a location in FR, to me. But my FR geogaphy is a bit weak at the moment.
Does anyone know if this will be the somewhat official 4e world?
The best way to think about this is that the answer to the question is no, but not because of the official or 4e, but because there's not a world as such. I think a lot of the WotC material released so far is about interesting individual locations, but not entire worlds. I think they are trying to provide stuff such that the DM or PCs can start expanding outward.
That said, you can get a long way towards creating a campaign world by using the published material so far - ie the Dragon articles, DMG information and info pulled from H1, H2 & H3.
Admittedly you won't have an overall campaign map, nor a deep and immersive history, nor will you have everything you'd want if you'd written it yourself. But you will have a lot of great locations that can be planted wherever you want, you'll have a lot of history (although you might need to put it all together in a way that makes sense) and you've got plot hooks galore for your own games.
So, no, there's no official '4e campaign setting'. There is, however, a vast amount of information available that you can build one from.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.