37Signals had a related comment in their Filter blog entry today, concerning the necessity of functional specs: "If you’re leading 50 people into an undiscovered country, and you have to convince the entire court of Spain and Portugal to fund your expedition, then you’re going to hire a bunch of guys with sextants to plot out your journey and guess where all the gold is. If you’re 5 guys in a boat, you’re just going to set sail and head west until you find land."
Kristopher Tate can manage to fly by the seat of his pants and make changes like that on the live server; Flickr now has to take a much more structured approach for several reasons, and that will obviously take them longer. It's 5 guys in a boat vs. 50 people in an undiscovered country.