I've had people tell me that setting up the SVN, moderating discussions in a mailing list, twittering project updates, and orchestrating the cultural/public facing side of the organization are the most productive early tasks.
My question is: will people start working on a project without even a line of code, or will there be paralysis until there is something to work off of?
That said, it would take exceptional circumstances for me to work on such a project. Programmer time has a high market value, and--personally--I'm still having a hard time not looking at your idea as asking programmers to work on your idea for free.
Project management that your discussing is a non-issue until the project grows considerably. I think for many programmers it would feel like you were just taking credit for their work, rather than providing a valued service. People become project leaders by contributing publicly recognized effort and talent to the project, and I just don't believe the efforts you are suggesting would be viewed as valuable.
You're confusing "my plan will work if other people behave this way" with "other people will behave this way".
Moreover, it's an open source project, so you can't say anything about "any ensuing corporation". You can only make committments for corporations that you control; you can't stop other corporations from getting most of the benefits.
And, who's to say that 6 is the right number? What if a given project takes 10 people to do reasonably? Why will those last four people contribute?
I guess 100% is the best way to structure it. Possibly even with a disclaimer saying the founder would not create any company out of the source code - but could be hired by anyone who does. The founder's role would then, simply, be an evangelist for the project(s).
I think the last four people would participate in the hopes of entering the top six, but a more open plan would probably encourage more participation. I think the last four would participate with the goal of entering the top 6, just like the dozens of applicants for the winner-take-all Ansari X-Prize.
I just think that having any plan for the future would make developers more likely to invest their scarce time.
If there's no code, what "project updates" are you twittering?
Note that all of those things are fairly low cost, so doing them isn't much of a contribution. They may add more value than the same amount of time spent implementing, but there will be far more implementation time.
All of these are definitely low value activities; the goal would simply be to reduce administrative overhead (time, not money). That way, contributors would spend more time doing the high value work and less time on BS. The goal would also be to foster a sense of community and make it easier for new members to join and get caught up on the big-picture goals of the project.