My previous games have all been, more or less a linear progression of play and thus design and implementation. MW2 however is taking on a more free form mode of play, where you can decide just what to do and when to do it.
What this means for development is that I am working to get the 'world' up and functional, with basic elements for transfer between areas, and the core gameplay mechanics of how you move about the world and interact with it.
Once that is complete I will move to implement already designed and design new quests in these environments.
In this way, with subversion it should be very possible for multiple gameplay programmers to implement quests that generally do not intersect with one another.
A strict system for shared information of accomplishment variables will be in place so that coding for completion of other quests is well understood.