NetNewsWire developer Brent Simmons (who just started a new job at Audible) wrote a fascinating post about his priorities while developing his apps:
The best general advice I can give is just this: make sure performance is part of the foundation of your app. Make sure it’s part of every decision every day. Make sure, in other words, that performance isn’t just a topping — it’s the pizza.
Even as a non-developer, I admire Brent’s commitment and methodology.