The winter Google logo, aka Doodle, for the first day of winter in the United States is not on Google.com. It is in Canada, Mexico, Germany, Poland, United Kingdom, Japan and even Kazakhstan but not the United States of America. I am not sure why, there is no other Google logo on the Google.com home page.
The picture above is the doodle, animated, in higher resolution than you'd see it on Google's home pages. Google normally has a winter logo for the first day of Winter, the Winter Solstice. You can see on the doodle page which countries you'd find this logo.
In some places, like Brazil, it is the first day of Summer or the Summer Solstice. It feels that way in New York, to be honest, but nope, it is Winter here. Here is the summer logo from Google:
Forum discussion at Google+.
Update: Around noon, EST, Google put the Winter logo live on Google.com US.
