From Age of Empires a highly successful RTS to an unknown MMO. This company has the Hutzpah to do it. Next Gen did an interview with Ensemble's crew in Dallas.
Hudson explains the origin of the project. "We've got a lead designer here, his name's Ian Fischer, he's been here for a long time. He's always wanted to do an MMO. He's been playing MMOs since the early days, MUDs, before that."
The idea was proposed to Ensemble right after Ultima Online came out. 'Why don't we do an MMO?' At the time, Ensemble was in no position to be thinking about it. But Fischer persisted ever since.
It's still in the "noodling" phase but don't be surprised if we hear an announcement in the near future.