While this sounds like a sudden change, it is apparently more of a long-term thought. The Register quotes Shuttleworth:
"Today we have a six-month release cycle," Shuttleworth said. "In an internet-oriented world, we need to be able to release something every day. "That's an area we will put a lot of work into in the next five years. The small steps we are putting in to the Software Center today, they will go further and caster than people might have envisioned in the past."
But given that many of Shuttleworth's thoughts became decisions later on, it might be interesting to see, where this one leads.
Interestingly enough, 5 years is about the time, when Ubuntu will run out of letters.