Previous announcements have stated that TES V would be built on a new version of the Gamebryo engine used in Oblivion and Fallout 3/New Vegas, but a Tweet from Bethesda Community Manager Nick Breckon stated, "We can now confirm that the TES V: Skyrim engine is all-new. And it looks fantastic." A followup answer stated that the engine was "a new graphics/gameplay engine built internally" and that more details would be forthcoming.
Boom!!!
/thread.

Like most people I've never had a problem with e engine, played it to completion twice on the 360 and another 2-3 times on 2 different computers with countless mod installed.
I do feel sorry for the vocal minority and this apparantly unfixable 'stuttering' they have, it's such a a good game.
Recently playing through Morrowind - great game once I realised the combat is statistic based as opposed to skill!
Gamebryo, I swear its already stated is a modified Fallout 3 Engine somewhere
I was thinking of Unreal Engine 3 (they wont of course) but it's never reached it's potential after the letdown of UT3.
I just hope its not as pants as Oblivion
Playing both Oblivion and Morrowind atm, I think Morrowind is better.
I will take a look at the new game when it finally arrives, but I won't be in any hurry to do so.
just didn't seem to any reason to explore the game in Oblivion as you were basically just given everything on a plate
I'd be suprised if its not using a branch of the idtech5 engine
it does massive terrains gorgeously, you can throw in stuff like speedtree with minimal work and the engine has been designed from the ground up so it can scale seamlessly to a target hardware platform including consoles, so they can develop the game in high-res on PCs and it will automatically be adjusted LOD, incidental object depth*, etc. wise with optimal performance and visual quality on the 360 with very little work from the developer.

