From what I've heard (I've heard Seamus speak about this in person) He started working on DirectX, but then he started tinkering w/ an idea of making a console, he got some other MS people into it, and they started developing a sales pitch to Bill Gates and the rest is history.
From what I gathered from his talks, I got the impression that he was the one who came up with the whole idea to begin with. But nowadays it seems that aspect is downplayed. I think cuz he speaks like a normal person and not like a PR person. But what the PR person fails to see is that the gaming community like the normal person and has a distrust of the PR person.
<< I'll take any opportunity to bash Microsoft, but in this case I do place my doubts. How do you conclude the X-Box isn't doing well from the fact that one of the people working on it got bored with his work and decided to do something else? He apparently got bored with his previous job too, otherwise he'd not have left DreamWorks. He was hired to work on DirectX, but started working on the X-Box instead. Two options: 1) He didn't like working on DirectX either, and was still looking for something else, which he apparently didn't find in the X-Box either. (Maybe he wanted to start his own business?) 2) He wanted to work on stuff like DirectX, but was put to work on the X-Box instead, and as he didn't like that kind of work he left. If Microsoft had fired half the people, or a lot of X-Box employees suddenly quit I'd have said 'Ok, something is not well there', but this is only one person. Not like DreamWorks died out when he left them either. >>