I've thought about the whole Skyrim setting, and my opinion is that I don't like it, has been this way from the start, and here's why.
If the game is set in Skyrim, what are the main colours that will be implemented into the game? Black and White... for most of the time you're exploring the wilderness you'll see rocks with black and shades of grey, and vast expanses of white covering the ground and trees and obstructing your vision with glare.
I want colour in my game. Please set the game in Eslwyr or Summerset Isles or Black Marsh. Please.
Stephen.
'Cause they're going to chance the game after developing it for 3 years because a single person doesn't think there'll be enough color, right?
When you think of Skyrim, don't think of just snowy mountains and frozen lakes. Bruma was high-altitude. And although it may be cold, have you ever seen pictures of http://www.taiga.net/nce/graphics/frontpage_photo_cropped.jpg?
Also, have you ever watched the series Planet Earth? They covered the Boreal Forests, and those places are probably one of the http://sealwyf.wikispaces.com/file/view/boreal-forest-arctic-circle-701234-ga.jpg/32308017/boreal-forest-arctic-circle-701234-ga.jpg I've ever seen.
Here, check out the http://www.uesp.net/w/images/images.new/3/33/Skyrim_map_Oblivion.jpg, and I'll explain my estimations based on what I know of Earth Science and Biology... although it doesn't really apply to Nirn that much, people are making estimations on Skyrim based on Earth anyway.
Based on what I know, the tallest mountain (towards the bottom center) would be barren at the top. There isn't enough consistent weather for trees and plants to grow on top of a mountain that big, it'd be covered in snow, have constant weather changes, and it would simply be too cold. Towards the base of the mountain, you'd get little "pioneer organisms" like Lichens. Which can actually be very http://www.adventurist.net/trips/e-rock_04-2001/gallery_12-04/lichen-3.jpg. In this area, you'd get animals that can digest lichens, I'd be thinking mountain goats and things like reindeer, but you never know with Nirn. Then you would get into the Boreal Forests when it starts to be a little less steep and cold, which have Pine Trees, Mosses, and Lichens. On Earth, they have creatures like Wolves, Reindeer, Elks, Moose, Bobcats, Rabbits, Bears, etc. but I'm sure Bethesda could come up with something much more creative.
When the land flattened out, you would start to get grasslands and coniferous forests. When I say grasslands, I mean http://upload.wikimedia.org/wikipedia/commons/f/fa/Efmo_prairie_2005.jpg, http://i300.photobucket.com/albums/nn11/letspaintnature/20080730_prairie.jpg, and http://www.co.benton.or.us/parks/hcp/images/Fisherbutte.jpg. And when I say coniferous forests, I mean things like http://i10.photobucket.com/albums/a123/HimeHikari/2894165921_1dcce3b361_b.jpg, http://www.uwo.ca/biology/Faculty/ensminger/images/bog_and_fog_small.gif, and http://www.ecosystema.ru/08nature/world/kun/06.jpg.
Then you would have the http://www.marietta.edu/~biol/biomes/images/tundra/alaskapipeline1.jpg to the North where it was too cold for other organisms. Which I pretty-much explained by the areas with Lichens, with the addition of hunters that wouldn't necessarily be on the steep mountains. (Let's face it, you fall, you're dead. Chasing prey requires running.) There are few predators on the tallest mountains of the Himalayas.
The real fun starts at the coldest and more snowy parts of Skyrim, and yes, I'm talking about the parts that are "black and white". Especially by the water! There you would get so many interesting sea creatures, and so many interesting land animals as well. There you've got things like penguins, seals, orcas, narwhals, polar bears, colossal squids, whales, foxes, belugas, and whatever the creative minds at Bethesda Softworks can come up with!
So basically, on the mountains there would be a mix of the Boreal Forests and the Tundra climate, farther down you'd get some coniferous forests, then in the valleys you'd get prairies (where else does the water flow?). The northern part of Skyrim, and by looks of it the Eastern parts of Skyrim would be the most cold. Towards the Western-Center (Near Markarth Side) is where you'd get lots of prairies and coniferous forests. By Solitude, Dawnstar, and Winterhold you'd probably have a mix of Tundra and maybe some small forests. Riften would almost definitely be in the Coniferous Forest zone, and Falkroath. Windhelm may be a Coniferous Forest Zone, or a Boreal Forest zone. High Hrothgar and Whiterun would probably be like the stereotypical "Dwarf" city, they'd be high in the mountains, cold, and snowy. Riften and Falkroath would be a lot of like Bruma, but I'd imagine the other cities would be much more different.
I'm excited for Skyrim, personally.
When we're talking economy based on environment and being close to borders, Riften, Solitude, Dawnstar, Winterhold, and maybe Markarth Side would be doing well. (Nords are natural sailors, so places near the water would be doing well) Whiterun and High Hrothgar would run out of water/food often, and wouldn't be able to raise many crops or get a lot of water unless they were imported, which would cost money, which as we all know, runs out eventually. Because Falkroath is surrounded by mountains, and near unpopulated parts of other provinces, more likely than not it would also not be the most wealthy.
Also, it's said that Skyrim expanded beyond it's previous borders more recently, including half of Dragonstar, and parts of High Rock.
That's just my estimate anyway, nobody's been there. For all we know there's a gaping hole in the middle of it that our characters will have to climb down and find and fight
darkspawn daedra.