I have been wondering why MovableType is not "open source". Six Apart announced TypePad, which is designed to capture more people who don't have their weblogs now, by offering user-friendly tools, according to the press release.
It seems to me that Six Apart expects more revenues from TypePad than MovableType. If so, making MovableType be open source to let others develop MT really makes more sense to me than making efforts on further development under supervision of Six Apart's very limited resources.
I think one of the drivers that let MovableType get popular is the combination of the well-shaped program (code) with its well-written documentation. It seems to me Six Apart is able to provide solid documentation that leads development efforts to certain goals, an easier job than completing everything by themselves.
BTW, how many people are developing MovableType and other products at Six Apart? Is it only Ben?