Like I commented in the thread. Goals are better than mission statements.
37signals missions statement comment ain't really viable in the WP case. 37 signals is a small close knit company where each individual have a good grasp of where the tools are going. They develop for themselves rather for their customers. They want to make the best tools that fulfills their own needs and requirements.
WP should not be everything for everyone. WP should have a focus point, WP should have a goal. Otherwise its just bland and nonprovocative, in other words somewhat boring.

WP consists of v nvr of code contributors, x nbr of idea makers, y nbr of actual code comitters. z nbr of final decision makers.
Having a goal for WP releases is a good thing I think. It prevents arbitrary dislikes of ideas because the disliker doesn't think WP should do that. It also could get almost everyone behind one single unified goal. If people don't like it they can work on something else. Not fork it =). I'm saying this as a harsh critique of WP politics. But most of my critique would be pointless if WP actually took a stand instead of releasing smokescreens.