No, there is a lot of environmental contrast between Skyrim and Cyrodiil. Skyrim's land will be quite a bit more varied, and those boring forests and plains you see in Cyrodiil won't dominate the world.
Not as much as the contrast ashlands - lush forest. Just take one of those pre Oblivion screenshots http://www.waiting4oblivion.com/images/screenshots/obliv31B.jpg and compare it with something like http://i.testfreaks.co.uk/images/products/600x400/40/morrowind.407592.jpg.
Huge contrast, while Cyrodiil / Oblivion isn't to that extent.
Although I agree with you and hope that the land will be more varied.
Edit:
http://www.waiting4oblivion.com/index.html
When will someone create waiting4skyrim.com site with all the info? (at least that that can be posted)