The most immediate concern for the Wiki Foundation is less the idea of an office with furniture and windows, or even the difficulties of collaboration, mostly it is continuity.
At the moment the founders are involved. They have an idea of what they want and how to achieve that. There are now thousands of regular contributors who are influencing that direction. There are millions of occasional contributors who muddy the edges. How do you ensure continuity?
One of the first development organisations I worked in 15 years ago was a student-run endeavour at the University of Cape Town. Every year hundreds of students volunteer and contribute to different projects. Each project is run by older students. Continuity is difficult where students graduate and leave each year. Sometimes entire projects vanish when the students who know how to run them fail to come back.
The solution was to employ a small band of professionals whose task is to make sure that projects are properly budgeted and accounted for, keep track of how the different projects interact, and ensure that the overall emphasis of the organisation remains focused. The professionals ensure consistency while the volunteers contribute fresh ideas, fresh thinking, new directions and lots of enthusiasm.
It has worked well for more than 50 years for this organisation.
Offices are far less important than continuity. And the more you rely on volunteers, the more important it is to have a solid base of professionals - where-ever they may be.