The earth wobbles. Fortunately, it wobbles slowly and regularly. Tomorrow morning, December 21 2013, its axis stops tilting away from the sun and begins to tilt closer. Result: in the northern hemisphere, the days get a bit longer. In the southern hemisphere, the opposite. For folks on the equator, all the hoopla above and below is meaningless: the days and nights remain the same length year round, mas o menos. See explanation on Wikipedia.
As a northern dweller, I welcome the winter solstice. This is the real and original holiday of the season. All the religious fuss and bother is a hijack job, now hijacked in turn by the commercial interests. Solstice is what there is to celebrate.
There’s no official winter solstice anthem, nor should there be. But George Harrison’s Here Comes the Sun probably comes as close as anything. Here’s five versions of the song, from YouTube, that I find particularly inspiring.