It's all, again, a gut-level sort of thing. But you're right when you say that projects develop all the time. Game development is an organic process. You HAVE to be open to change during production. The best pre-production process won't make a game great.
Greatness only comes during the hands-on process of production.
I suspect that some games require less and I can't really imagine taking much more than that. The DX team did a comprehensive post-mortem of DX1 after we shipped. And Harvey Smith, who's acting as project director on DX2, put together a remarkable list of DX1 problems, which he and the team fleshed out with some proposed solutions. But it's just too early to be talking about DX2 right now. Ok, Warren, thanks for your time.