Seems it's a career-long motto of his. Here's my little story from when he told that to a room of record labels in 2003: http://www.oreillynet.com/onlamp/blog/2004/08/say_no_by_defa...

==

In June of 2003, Steve Jobs gave a small private presentation about the iTunes Music Store to some independent record label people.

My favorite line of the day was when people kept raising their hand saying, "Does it do ___(x)___?", "Do you plan to add ___(y)___?".

Finally Jobs said, "Wait wait - put your hands down. Listen: I know you have a thousand ideas for all the cool features iTunes could have. So do we. But we don’t want a thousand features. That would be ugly.

Innovation is not about saying yes to everything. It’s about saying NO to all but the most crucial features."