There really is no reason to do the "how dare investors disrespect the company I love!" thing every time a stock goes down for valid reasons. Dropping from 20M down to 17M on the projection is a darn good reason for some investors to think a situation isn't quite as nice as they thought initially. I mean, seriously. I don't see why that would upset anyone.
If anything, given Nintendo's reliance on big first party titles and the holiday season, it looks to me like a good opportunity to sell high then buy again later in the year.