According to the latest "Ask us anything", a huge amount of Tamriel won't be available at launch.

So far it's been confirmed that the only available area of Summerset Isle will be Auridon, which is the island comprised of the cities of Firsthold and Skywatch. As you can see http://images.uesp.net/c/c9/Summerset_Isle_map_Oblivion.jpg, it's not that big.

And then there's http://images.uesp.net/f/fe/Elsweyr_map_Oblivion.jpg, which seems to have really suffered. No non-humanoid Khajiit NPCs will be present, and Dune and Fort Sphinxmoth appear to be the two towns at launch (one of which isn't even a real town, just an Imperial fort), as well as a not-existing-in-lore island off the south coast.

Nothing has been said about Valenwood, but it could go one of two ways: it could be the most fleshed-out area, or it could also have two cities playable.

If we work under the assumption that each alliance has a roughly similar amount of content (and I hope they do, since it's not like we can explore the other ones), then it seems fairly logical that the other alliances will also have at least two cities per province.

I'll be honest with you. I'm not impressed by this. I'd really like to play this game at launch, but exploration is a huge part of the reason why I like TES games, and it looks like that's not really the focus of this game: my reasoning being, if you're gonna give us the whole of Tamriel to play in, well, I'd like to play in the whole of Tamriel. Otherwise, what's the point?

I think it has yet to be determined. Or so I hope. Every new revelation in regards to the lore and setting is making me less and less hyped.

Same here. Personally I would have rathered they just gave us, I dunno, the entirety of Hammerfell, with the three alliances fighting over it, and then added the rest later.

One huge, complete province, to me, sounds better than nine with less than half of the land playable.

I predict a lot of area will be available post-release as expansion packs.

I was surprised when I read that article/dev's answers. The area seems tiny; it doesn't look attractive at all. They're giving us a non-existant island and very little of the actual land we wanted to see. If I planned to play the game, I would be disappointed.