The terrain is snow, trees, mountains, and some valleys. It's not that impressive, and it's all covered in snow. I hate snow. Skyrim is a copy of northern Cyrodiil. It's going to be snowy with some trees and mountains.Cyrodiil has snow in the north(It's nice, but to have an entire game covered in snow sounds boring), forests in the east, swampland in the south, hills in the west, and mountains in the north and east. Skyrim has snow, mountains, and some trees. It's going to be a copy of northern Cyrodiil. What kind of terrain are you expecting? Just how varied can snow be? There are mountains, valleys, a few rivers, and some trees, all being of the same variety. Skyrim's architecture is the same as Bruma's. Skyrim really isn't varied.
Hahaha! Don't worry about it man, it's far more than that
Northern biomes are composed of boreal forest and tundra, two of the most interesting ecosystems in the entire world, particularly the boreal ecosystems. Also keep in mind that northern Cyrodiil was only covered in snow because of the elevation - the Jerall Mountains. Despite the border regions showing snow further north, i'm sure that's going to be changed for TES:V. As the player decends those mountains into Skyrim, the snow will dissipate, and you'll venture into some of the most fascinating cold-climate regions in all of Tamriel. Cold doesn't mean snow. Cold just means cold.
Expect Boreal forests like http://bioweb.uwlax.edu/bio203/s2009/nelson_lau4/boreal%20forest%20dr%20volk.jpg.
Tundra expanses like http://www.bio.miami.edu/dana/pix/tundra.jpg.
And scenic lakes like http://www.great-adventures.com/images/canada/Emerald%20Lake.jpg.
And that's before reaching the beautiful snowscapes ^_^