File formats are interchangeable, the engine is most likely the same, it was gamebryo(which is a rendering engine) that they replaced with their own stuff.
Kind of like how people think games made in unreal engine always have bulky space marine characters and gray plastic looking environments covered in glowy bits because the engine works that way.
^ QFT, a friend of mine complained that CE3 engine is very good for games with Mecha in them, and that UDK makes bulky rough skinned marines look cool, while if you want for soft delicate skins like that of a sexy female warrior, then you need to use the Crystal Engine (FF13) and that no one engine can make everything look…
from Kotaku "Elder Scrolls V: Skyrim's new engine is capable of creating actual human faces. And as you can see above, rather attractive ones at that." Oh so the Engine makes the faces, all this time I thought it was the character artists! That's some primo game journalism there.
I thought they said skyrim uses an in house engine and not gamebryo? The game acts the same as the others in every way, even the file formats are the same
This engine doesn't look like a huge improvement over the other one.. Sometimes it looks incredible but other times it looks awful and fullbright-esque!