Who cares if it's bigger, nobody's going to notice. Cyrodill was big, Skyrim will be big.
Does anyone even explore every single nook and cranny anyway?
Why I care and why I think it can be noticed:
1) It risk making the world feel very cramped up, which is something really bad in my opinion. It would be too much (in my opinion) if you pass a dungeon every 30 seconds, like it was http://s2.n4g.com/media/11/newssi/15000/18861_0_org.jpg, for instance.
2) You'll never be able to have huge, majestic mountains and valleys. The scale of everything thing might result in be treated as a joke. You can most likely say good-bye to landscapes like... http://www.ozoneeleven.com/wp-content/uploads/2010/08/Mountain_Valley_1600-x-1200.jpg, http://www.cpawsbc.org/files/athead_Valley_from_Global_TV_helicopter_ride.jpg, http://www.naturewalls.org/wp-content/uploads/2010/05/beautiful_nature_in_the_mountains_wallpaper.jpg, http://www.wallpaperpimper.com/wallpaper/Landscape/Landscape/Valley-Vista-1-RP6ONRV6I8-1600x1200.jpg and http://2.bp.blogspot.com/__mMx7lCefGY/SxEn5CGyUAI/AAAAAAAAAvU/6w8jUlJmrTY/s1600/North+Klondike+River+Valley.png.
If landscapes like that would be in Skyrim... it would never fit. Any of those landscapes in the pictures would pretty much take up half the map/world space or even more. If landscapes like that would be in Skyrim; they would have to be greatly reduced in scale, which I think would remove their whole "greatness" and "epicness".
3) With a promised much greater draw distance; the world could risk feeling even smaller than Oblivion, since you would practically see the whole map from anywhere. Even though I'm not 100% sure of this, it's a possibility.
4) You might be able to run from one end to another of the map/game world within 15 minutes, like you could in Oblivion... making it
feel even less big.