Was said here less than a month ago,
Howard wouldn't be drawn on many details about the game, but said the technology was derived from the engine that powered Fallout 3, albeit with significant modifications.
"Fallout 3 technically does a lot more than Oblivion. The new stuff is an even bigger jump from that," he said.
"I can say it is on the existing platforms, which we're really happy with. You almost feel like you have a new console when you see the game."
So it apparently is as big or bigger of a jump over Fallout 3 as Fallout 3 was over Oblivion. I didn't think they jump was that huge. Anyway, same engine.