Any big feature change makes for a good slide or two in the keynotes. They get once or twice a year to make a big impression on the press - dribbling out updates to core apps in the meantime would remove the buzz.
It's certainly made a big impression, though perhaps not the kind they were after. Revealing something in a keynote talk leads to more scrutiny so making a big deal out of something that isn't ready doesn't seem wise to me.