Skyrim is actually smaller than Cyrodiil on the map, so the fact that it's about the same size as Oblivion's map is pretty lucky.
Fast travel is still optional. Nothing is forcing you to use it.
Skyrim won't be as vibrant as Morrowind because its mostly tundra and ice and snow. Not a lot of room for crazy flora. But there WILL be more interesting beasts, which is good. Probably not a whole lot of "Oh hey I saw that animal when I visited my local mountain." (for those of us who live near mountains
)
But I'm a bit disappointed with the 20 hour main quest... I wonder how accurate that is. But there should be another 30 hours at least of side content accessible for ANY character, no matter what kind of character they play. I think this will be true because they say the game can generate quests based on your play style.
As long as I get a 50+ hour game I'll be happy. Dragon Age took me over 55 hours for ONE playthrough, and it wasn't even a free roam game. Now I expect no less.