Microsoft have always been quite forward about their expectations for Kinect and that doesn't seem to be slowing down. This recent claim suggests that they believe Kinect will outsell the iPad convincingly.
Speaking to Gamasutra, Kudo Tsunoda, who's the creative director on Kinect said "The pre-orders have been really strong. As far as what we're looking at for Holiday, this is going to be stuff that'll blow away any of the sales you've seen with iPad."
When the iPad launched earlier this year, it managed to sell one million units in its first month.