The mountains will definitely have snow and ice just like they do here in Colorado and other places across the world. But if you look at a region like Colorado it's not just Mountains but a place of grassy plains, deserts, rivers, lakes and forests. In my mind the places near the ocean will look a lot like Alaska's (or Scandinavia's shoreline). There will probably be dense forests but in the more southern regions of Skyrim it will probably look like the great plains and maybe even have a cold desert.
Anyway I think what made Morrowind unique wasn't just the varied landscape but it's plant and animal life as well. Morrowind didn't even have snow capped mountains until Soltheism when I think back. Landscape isn't too important to me (I mean I want it to be more varied than Fallout 3) what's important is the experience and freedom.